A female friend overheard me on the phone with my boyfriend and became concerned. He and I tease each other relentlessly, calling each other mean silly names, but it's all in fun. Though we have a very loving relationship, she thinks the teasing is a sign of submerged anger. Is she right? And are we doing something damaging?

--Banterer

Yesterday, on the phone with my boyfriend, I had to ask him to repeat something he'd just said because I'd become briefly mesmerized by a big fern shimmying in the breeze. No, sadly, I wasn't all "Sorry, I missed that bit because my couch caught fire." The man was competing for my attention with a plant.

It isn't that he's boring. I have ADHD -- attention-defici...sorry, what was I saying? And in our relationship, as in yours, teasing plays a big role. So when my boyfriend has something important to tell me, he'll sometimes prepare me (with a line that always makes me laugh): "Do I have your divided attention?"

Teasing like this is what social psychologist Dacher Keltner calls an "indirect, playful way to negotiate conflict." This is especially important in a relationship, where there are many conflicts and annoyances you'll never resolve. In mine, for example, in addition to my midsentence day trips to the Baltics, there's how my boyfriend seems to have attended the Jackson Pollock school of culinary arts. Or, as I put it -- while cupping an ear theatrically and looking upward: "What's that? ... Um...honey, the ceiling says it ordered its sauce on the side."

Teasing is like bullying, Keltner explains -- in that it's something you say or do that's intended to provoke another person. However, teasing includes clues that what you're saying isn't to be taken literally -- and that your intent is playful, not hurtful. These playfulness signals are called "off-record markers" and include laughter, obvious exaggeration, a jokey tone, mimicry, and contorted facial expressions.

As for the concern that your teasing is endangering your relationship, on the contrary, Keltner and his colleagues found that "couples who playfully teased, as opposed to resorting to direct, cogent, but ultimately hackle-raising criticism, felt more connected after (a) conflict and trusted their partners more."

And the reality is that only two people who truly love each other can get away with trash-talking each other in extravagantly awful ways. This is an example of what behavioral ecologists call a "costly signal" -- one that, through its expense or riskiness, tells you it's more likely to be for real. Conspicuous consumption is an example -- signaling that you've got money to burn by shelling out $8K for a Rolex when a $50 Swatch tells the time just fine. So, sure, there are many ways to express romantic appreciation, but it's nice to opt for something unique, like "What a wonderful love note -- made all the sweeter by handwriting that looks like that of an 8-year-old locked up after multiple disappearances of neighborhood pets."

My boyfriend recently got laid off and lost a bunch of money in stocks. Yesterday, feeling blue, he said, "Can't anything good happen for me?" (Gee, thanks. Guess I'm nothing good.) I know he's talking about financial and career stuff, but we have something pretty special together. Why is he focusing on the bad stuff and not appreciating the good? Money isn't everything.

--Undervalued

A guy likes to have a way to buy his woman dinner that doesn't involve a ski mask and a sawed-off shotgun.

No, money isn't everything, but that can be difficult to remember while panicking that you'll soon be raiding the market share of the wino on the corner begging for change. Also, because women evolved to go for men with status (a cue for the ability to provide) and men coevolved to recognize this, it can be especially hard on a man when his career trajectory goes from riches to rags.

However, emotions are -- at root -- behavior management tools, and the feel-bad that comes with a loss in status pushes a man to go out and get a new job and make new investments. Without that motivation, that couch in Grandma's basement can start looking like an extremely attractive place to be from 9 to 5. And 5 to 9: "Yo, Gram, can you throw down another bag of Doritos?"

What you can do is be fierce in telling your boyfriend why you believe in him and about all the things you respect and admire in him (especially those that employers will also respect and admire). This is the sort of "appreciating the good" that he needs -- especially if he gets to the point where he's driving a brand-new Tesla but only until he gets a $2 tip for bringing it back to the guy who owns it.

I'm a single guy who started a "friends with benefits" thing two months ago with an unhappily married female co-worker. We've since developed feelings for each other and started talking about a future. I'm worried because people always say, "If she cheated with you, she'll cheat on you." And because she's unhappy with her husband, does that mean she'll eventually be unhappy with me and see it as reason to cheat?

--Hesitant

There are many people who cross ethical lines at work, but most of them just do it by taking home Post-its or a stapler.

Okay, sure, have a FWB thing, but with a married co-worker? What happened -- too overworked to swipe right on Tinder? And as for why your co-worker started, uh, outsourcing her sex life, there's an assumption that people cheat because they're in crappy marriages or relationships. And maybe her marriage is unhappy. But infidelity researcher Shirley Glass found that even people in happy, loving marriages can end up cheating. They do this for a variety of reasons: more sex, better sex, different sex (men especially go for variety), or sometimes just because "she isn't bad-looking and there's an empty office with a big couch two doors down."

As for whether this woman would cheat on you, that depends on whether she's the sort of person who cheats. And no, that isn't as idiotic as it sounds. Evolutionary psychologists David Buss and Todd Shackelford found that there are personality traits common to people susceptible to cheating. One of the strongest predictors is "narcissism" -- a personality trait marked by self-importance, self-absorption, a profound sense of entitlement, and a lack of empathy.

Another big predictor is "low conscientiousness," reflected in unreliability, disorganization, laziness, and a lack of self-control. And finally, there's the unfortunately Norman Batesy-sounding "high psychoticism" -- researcher-ese for a mix of aggressiveness, impulsivity, and an inability to delay gratification. Sound like anybody you've met in the janitor's closet recently?

Even if this woman checks out personalitywise, you'll have a much clearer picture of what's possible after she gets divorced. That is, if she gets divorced -- if this thing with you doesn't turn out to be "affair-apy" (a little sexual tide-me-over until she can patch things up with her husband). Regardless, you should take the time -- a year or more -- to parse who she really is and whether she and her husband are simply two (irreconcilably) different people or whether he just watches a wee bit too much ESPN when he comes home. If you're lucky, you'll find these things out from her, and not in some awkward moment at the end of the workday when you finally get a chance to, uh, chat with her husband -- through the windshield as you're clinging to the hood of his moving car.

I'm a woman, married for a year to a great guy. The problem is that he's too gentle when he touches or kisses me, and I'm starting to get really frustrated in bed. I know I should have let him know what I really like a long time ago. How can I do this now without hurting his feelings?

--Embarrassed

It's hot to have a husband who's kind of an animal in bed -- except if that animal is Hello Kitty.

Words, who needs 'em? Maybe you figured he'd get the hint from your body language -- maybe because you're pretty sure you would have if the tables were turned. Well, research by social psychologist Judith A. Hall finds that women are far better at spotting and decoding nonverbal messages (in facial expressions and body language). This makes evolutionary sense, considering a mother's need to suss out what's wrong with her 6-month-old (who is unable both to speak and to get on the internet at 3 a.m. to self-diagnose his diaper rash as a brain tumor).

Still, you don't have to give him a poor performance evaluation (ouch!) or go into sex ed lecturer-like detail. Instead, take the Gene Hackman approach. Hackman reportedly informs movie directors that the only directions he'll take are "louder, softer, faster, slower." (You might want to supplement those with "harder" and "rougher.")

To encourage greater openness, ask him what his sexual fantasies are (which should lead to the question, "Well, what are yours?") -- and do your best to deliver on any that don't involve illegal acts with livestock.

You might also watch movies together with sex scenes that are more "G.I. Jane" than Jane Austen -- like the 2005 movie "Mr. & Mrs. Smith." Then, when you're in bed, suggest "Mr. & Mrs. Smith-style," and he should get what you mean. Before long, when you tell your friends that sex with your husband is "dreamy," it won't be because you usually doze off during it.

I've always been a very athletic guy. I do jujitsu every day. When I don't exercise, I feel depressed. My girlfriend, however, has never been very physically active. She has a great body -- naturally slim -- without doing anything, which is probably why she's unmotivated to work out. I just think that if she did -- even a little -- she'd look like a superhero and feel better. I keep urging her to exercise, but it's not working. How do I encourage her?

There's that saying, "You are what you eat." Apparently, your girlfriend ate a supermodel.

Numerous studies find that exercise is a mood booster and improves our cognitive abilities (like memory), even protecting them into old age. Incredibly, a study on female twins by geneticist Tim Spector found that those with fitter leg muscles showed fewer signs of aging in their brain 10 years later. But we humans have a very now-oriented psychology. So, for many people -- like women who shave their legs before stepping on the scale -- these pluses are merely fringe benefits of workouts for jiggle management. And unfortunately, when your girlfriend looks in the mirror, she sees that all those runs to the vending machine seem to be paying off.

It's sweet and loving that you want her to have the benefits of exercising, but stand back, because I'm about to make a big mess slaughtering a sacred cow. Dr. Michael Eades and Dr. Mary Dan Eades, low-carb pioneers whose evidence-based approach to dietary medicine I have great respect for, dug into the research on exercise after meeting professional fitness trainer Fredrick Hahn. They were surprised at what they found and ended up writing a book with Hahn -- "The Slow Burn Fitness Revolution."

In their book, they note that many of the ways people exercise actually don't do all that much for their bodies or long-term health. For example, they say that many endurance workouts -- like the 7-mile runs I used to do -- are "tremendously inefficient" for improving health and often come with some serious costs, like the need to have your knees rebuilt with medical Tupperware.

They also write that many sports that people consider exercise -- including tennis, skiing, and (sorry!) martial arts -- have some fitness benefits but would better be considered play. They explain that exercise should do all of the following: 1. Make you stronger. 2. Improve your cardiovascular system. 3. Help you lose excess body fat. 4. Improve your endurance. 5. Improve your flexibility. And 6. Preserve or increase your bone density and muscle mass.

The one exercise that does all of these things is slow-motion strength training. This involves lifting extremely heavy weights -- weights that you can barely lift at all -- extremely slowly. You do just three to six reps in 60- or 90-second intervals -- to the point where your muscles just scream and give out.

By the way, though it says on the cover of their book that you can change your body by working out like this for just 30 minutes weekly, Mary Dan Eades told me that you really only have to do it for 12 to 15 minutes a week but they figured nobody would believe that.

Now maybe you're saying, "Come on...weightlifting for cardio?" Consider that your heart is a muscle and muscle cells need oxygen as they work. Mike Eades explains on his blog that conditioning your muscles through strength training makes the body more efficient at getting oxygen into muscle cells, which is what improves your cardiopulmonary function -- not all the pound, pound, pound of a run.

As for how to get your girlfriend into this kind of exercise, first, it helps to explain that it requires a ridiculously small time commitment -- far less than it takes for her to do "natural look" makeup (which, ironically, can take 40 minutes or more to apply). Of course, there's still the problem of motivating her -- considering how all she has to do to fit into her skinny jeans is have a plate of french fries and a nap.

Well, when you're in a relationship, you get to make requests of your partner -- things you ask them to do simply because it would make you happy. Put your request in that light, but give her an attractive (rebellion-quashing) timetable: For just three weeks, try slow-motion strength training with you. If, after that time, she hates it, she can stop. Mary Dan Eades explains that the three-week "try this" allows a person to experience some benefits, which often motivates them to keep going. If she does really get into it, be prepared: This eliminates any need to drag you kicking and screaming to the altar; she can just hoist you over her shoulder.

I'm a 44-year-old woman who's been dating a successful actor for a year. When we met, he told me he was 35. Well, in picking up a prescription for him, I discovered he's actually 42! I'm relieved -- but miffed that he lied. I've felt uneasy about being so much older (especially because his previous girlfriend was 24). He said he'd been meaning to say something and he was glad I found out. He explained that as an actor, it's important to be viewed as young. (His agent doesn't even know his real age.) He seems to be a good person, but I'm wondering what else he's lied about. I don't lie, and I don't want to be with someone who is a liar.

--Worried

Welcome to Moral High Ground, population: you. Wow, so that's your real weight on your driver's license?

The truth is, we all lie -- yes, all of us -- which is why social psychologist Bella DePaulo explains in her research on lying that people can't be tossed into "one of two moral bins, one for people who are honest and the other for the liars." DePaulo explains that you are lying whenever "you intentionally try to mislead someone." This includes telling your friend "I completely forgot you were performing at the coffeehouse!" or assuring her that her new haircut looks "cool and edgy," and not like a small animal that got hit by a car.

However, there are different kinds of lies, and the kind your boyfriend told is an "instrumental lie" -- a strategic lie people use to take a shortcut to something they want. This kind of lie is common to Machiavellian personalities -- schemers who manipulate other people to get their way. It's also linked to having crappy relationships, since you can't very well be close to somebody who's frequently pretending to be somebody else.

Ruh-roh, huh? Maybe not. Context matters -- including why he lied, why he didn't tell you, and whether his lie has lots of brothers and sisters to keep it company. If he doesn't seem to be a big truth shaver, consider that this age fibbie may be a necessary evil -- a "cost of doing business" lie. (In poetry, "Beauty is truth, truth beauty." In Hollywood, truth is unemployment.)

Why didn't he tell you? Maybe because he didn't tell you, and then he still hadn't told you, and then it seemed he was way late in telling you. If you don't see a pattern of lying, maybe this is a sign, not that he's a terrible person but that he dreaded disappointing you. You and he could even turn this incident into a positive thing -- an opportunity to come up with a policy for honesty in your relationship. What's especially important is making it a safe place for telling the truth -- pledging to sit down and talk stuff out instead of going all explodypants over it. This includes shocking Hollywood revelations like his current one, which -- frankly -- is too ho-hum to even make the wastebasket at TMZ. You've merely discovered that the guy's another age, not that there's another woman -- the one he's always dreamed of being.

I'm a man who respects science and tries to live rationally, and I'm dating this truly great woman who, unfortunately, is into astrology, energy healing, past lives, and other ridiculousness. I try to be open-minded, and I've been telling myself, "Hey, people can be different and still be together." However, she recently told me she'd seen a giant space worm out of the corner of her eye. It was 4 feet tall. Come on.

--Reasonoid

Yes, "people can be different and still be together." In one case, headphones made this possible -- for a sweet guy who cheers up by listening to death metal but fell in love with a woman whose favorite music video scene has the von Trapp children skipping around the Swiss Alps in drapes.

Unfortunately, there's no nifty audio technology to block out the lack of respect you feel for your girlfriend when you hear about her getting pony rides from a space slug or refusing to eat chicken when the moon's in Aquarius. A lack of respect for your partner's beliefs (as opposed to finding them merely odd or infuriating) is the starting line for contempt -- the amped-up form of disgust -- which marriage researcher John Gottman finds is the single best predictor that a relationship will tank.

So, in vetting partners, yes, it's good to keep an open mind. However, as the saying goes, just "not so open that your brains fall out" -- and you come to hear, "Hey, honey, the kids and I will be home a little late. They're running an hour and two ritual slaughters behind at the primary care shaman."

My girlfriend tells her mother and her friends pretty much everything. Literally four of her friends and her mom were weighing in on her recent urinary tract infection. I just don't get why she feels the need to let everybody know her business, and it's the opposite of what I do. I'm very private, and I'd like us to have some things that stay between us -- especially stuff that goes on in the bedroom. How would I set boundaries like this? And does this mean that we are ultimately incompatible?

--Uncomfortable

Being compatible with somebody doesn't mean you're like them in all ways. I'm an extrovert, which is to say I see a dead car battery as an opportunity to learn about some tow truck driver's childhood in Guatemala. Contrast that with my introvert boyfriend, who recently turned down an invitation he got to this really cool event, telling me, "I already said hello to somebody this week."

Beyond individual human differences, there are also some male-female differences, like in feelings- and information-sharing. Sex differences researcher Joyce Benenson explains that men evolved to be the physical defenders of the species, and it would have put a man at a deadly disadvantage to show the enemy his emotions -- like if he went all scaredypants from fear: "Oh my God, is that the enemy? I'm gonna throw up."

Women, on the other hand, evolved to build support networks and avoid social exclusion by convincing other women that they aren't a threat. A woman does this not by hiding her vulnerabilities but by putting her problems and weaknesses on parade -- a la "My ladyparts have been declared an EPA cleanup zone!"

In other words, your privacy nightmare -- the scrapbooking circle getting together to focus-group your medical issues -- is your girlfriend's emotional comfort zone. But this isn't necessarily a sign that your relationship is toast. For a relationship to make it, you and your partner don't have to be the same; you just have to have enough in common and be loving in dealing with each other's differing weirdass needs.

If there were such a thing as psychological catnip for humans, it would probably be feeling understood. So, tell your girlfriend that you understand it helps her to hash things out with her mom and the ladypeeps and that you think that's great. You're just wired differently. Explain how, and then -- sweetly -- make your request: You'd feel most comfortable if what happens between you stays between you...given that your idea of openness involves making people sign a 30-page nondisclosure agreement before viewing the heavily encrypted photos -- of Steve, your dog.

I'm a woman who's had a casual hookup thing with a guy for almost two years. I want a serious relationship, and I really like him and would like it to be with him. When we're together, we have a great time, but he can go a week or two without contacting me. Last week, he showed up late to my birthday, with no present and not even a card. I know I should cut him off, but the sex is great, and there's nobody else on the horizon. Any chance he'll finally realize I'm a catch and come around?

--Hoping

The guy didn't even give you a birthday card. Even the car wash gives you a birthday card.

Any guy with an IQ exceeding the highway speed limit gets that birthdays are a big deal to most women. And if you care about birthdays and a guy cares about you, he'll step up -- at the very least by running into a drugstore, grabbing a card, and checking that the pre-printed heartfelt message inside isn't "To my very special grandson! On his very special day!"

In a hookup situation, it actually isn't crazy to hope for an upgrade from sexfriend to girlfriend. In a survey by Kinsey Institute researcher Justin Garcia, 51 percent of the people who had hookups went into them hoping to kick-start a romantic relationship. In another survey, 9.8 percent of hookups led to committed relationships. However, there's a progression that takes place in going from lust to emotional attachment. It has a hormonal profile and a general timetable, and, well, two years into a sex thing, the attachment train is probably well out of the station.

In other words, it's time to take this relationship to the next level -- "the end." On a positive note, it's possible that removing yourself from this guy's life will make him realize that he loves you and needs you in it -- leading him to start showing boyfriend-type attentiveness. Either way, you're setting yourself up to have a man you can count on to be there for you -- and not just naked and at the ready whenever his Wi-Fi goes down.