My wife and I have our differences in bed. Let's say that I like A and she likes B. So we alternate -- A one time and B the next -- meaning we're each only satisfied half the time. Is this a smart compromise?

--Curious

Relationships do take compromise -- especially when one of you's in the mood for foreplay with whipped cream and strawberries and then a glance at the calendar reveals: "Oh, crap. It's Medieval Torture Device Monday."

As for whether your sex compromise is "smart," it depends. Research by social psychologist Shelly Gable finds that in a relationship, you can do the exact same activity on your partner's behalf -- say, picking up their thumbscrews from the welder -- and have it be good or bad for the relationship, depending on your motivation.

Couples in Gable's studies were happiest when partners' efforts for each other were driven by "approach" rather than "avoidance" goals. "Approach" involves moving in a positive direction, making an effort for positive reasons -- such as barking like a gibbon in bed because you love your partner and want them to be happy. "Avoidance" involves doing it to prevent rejection or conflict (like being exiled to the couch for three days).

An "approach" approach to sex, especially, appears to pay off. Social psychologist Amy Muise found that partners who took pleasure in giving their partner sexual pleasure "felt more satisfied and committed both at the ... time and three weeks later." The message in all of this? A smart sex compromise runs on enthusiasm for rocking each other's world in bed -- even if the thing your partner's into plays for you like "How 'bout we sneak out to my car for a quick endoscopy?"