If you don't want to share, you really only have one choice: make him choose. Clearly, however, he already has, so your only option is to move on.

Earth logic is really hard for some people.

"Just call this man and say goodbye."

Absofuckinglutely right. I once had a man tell me, after a few passionate months of dating, that he had a problem -- he'd met another woman and was "feeling torn" between us. I said "I'll solve your problem. You just chose her." I went home and cried my eyes out, sure. But I was also pretty proud of myself. Come on, LW -- the new lady isn't the one mucking up your relationship. That would be your dude. If you want monogamy, you should have been out the door the minute you found out about her.

I don't think she's that upset about him cheating as such - she describes their relationship as "on-and-off" and obviously knows about what he's doing. It sounds like she's genuinely concerned that he hasn't been so up front with his other partner. Which is pretty despicable.

A friend of mine was in much the same situation - she was seeing a guy for a while (not exclusively, on both sides) and he was stringing along some poor girl for months who thought she was his only one. My friend turned up at his house unannounced one day and they were in his car together. She worked it out pretty fast when he didn't know how to introduce them, but when the other gf asked who she was she said "I'm the person he sleeps with when he's not with you". The other gf had *no* idea there was anyone else. My friend was more worried about her than anything else, and told her to go home, then told him to get out of her own life into the bargain.

I don't think the LW cares about monogamy, just the integrity of a bloke who would lie to someone like that. Which is adequate reason to dump him. Warning the other woman is pretty justified too.

Unlike LTW, I don't for a second believe the LW's motives are pure. However, I do agree that the other woman needs to be told.

In my twenties I was on the marriage path with a guy I loved madly. We weren't engaged, but we were discussing rings, ceremonies, china, and so forth, and I knew he intended to propose.

It turned out he had a side piece at a client site in another state. He would have sex with her while he was there on business, which was once a month or so, but he told her his job made it impossible for him to have a girlfriend. He thought this would keep her from asking for more.

She started asking around about him and found out about me. Then she told him he had 48 hours to tell me the truth, or she would tell me. He did, as the clock ran down, in a pathetic e-mail. I'm grateful that she did it. She kept me from making the biggest mistake of my life.

(Later I found out there were many other women.)

I agree with Nicole. The LW's motives are not pure. My guess is that she has convinced herself that she is really is his one true love, but that she is just waiting for him to realize it. I'll bet she has created a bunch of elaborate excuses in her head as to why he won't, or can't commit to her. His relationship with this new woman is different from what he has with her and it bothers her; most likely bc he is acting more serious about this new woman. Lw needs to give it up. She was never anything other than a booty call during this guy's dry spells.

LW...admit that is over and refuse to take his calls. Get yourself out in the world and meet new people. Forget this other girl. If you call her, you will just look like some crazy ass stage 5 clinger. Let her handle her own problems, you have demeaned yourself enough for one life time.

So often, I have to talk friends out of writing or calling other women - their ex's new girlfriends, etc - to supposedly "warn" them. It only makes a woman look desperate and foolish.

First of all, it's really none of LW's business what this woman knows or doesn't know, and, secondly, their relationship may be entirely different than hers with him, so any info she has to offer is pointless.

Usually, this is merely about wrecking the new relationship under the guise of "helping" the new woman. It's ugly and selfish, and whether it works or not, the first woman has revealed those ugly qualities, which makes her even less attractive to the guy.

Also agree that LW motives aren't pure ("...telling her I was here first..."), and she needs to quit being this guy's dick holster. I can't say whether she should inform the other lady or not- I do think the new girlfriend would be better off knowing, but having it come from someone she'll no doubt view as a jilted psycho won't be that effective. I don't know if I'd even believe something some anonymous person sent me.

If I recieved a message from another woman like this when I'd just started dating a guy, I'd be like, "So what?". LW obviously isn't in an exclusive relationship with him and the new girl probably isn't yet either. Unless they've had the talk and committed to monogamy, most newly dating couples assume there are other involvements.

Now, if he was married to this woman - or about to be married - and sleeping with LW, I'd agree she'd have a valid reason to tell, but under these circumstances, it just comes off as jealousy.

My guess is that LW is more of a "friend with benefits" because he's openly told her that he's seeing someone else. He's not hiding it from her, yet he hasn't told the new woman that he has a fuck buddy - he has no obligation to reveal this to someone he's just started dating. But not doing so also suggests that he's more serious about the new woman and doesn't want to scare her off, which is probably what's really bugging LW.

"long-term on-and-off relationship"

Well there's your first problem.

The decent thing for him to do would be to tell the new woman about you. It may or may not make a difference to her, but she has the right to decide that for herself. If he thinks what he's doing is fine, why keep you a secret from her?

If you tell her yourself, you will look jealous and pathetic. She may not even believe you. And if he finds out, your relationship with him, such as it is, will be over. If you know it should be over but can't quite bring yourself to cut the cord, telling her will probably accomplish that. But it would be much easier to just end the relationship yourself, now, with some dignity.

Yeah, you'll look jealous and pathetic and she may not believe you.

Tell her anyways, in case she doesn't know. It's up to her what she does with the info.

Don't NOT tell her about the risk she's incurring because you're worried you'll look jealous and pathetic. You will. But it doesn't matter.

What's more important, her having the info she needs to protect herself, or whether or not you look good?

That's a different take, Nicole. I agree that she shouldn't care how she looks if she's really saving this woman from being duped or used, but my impression is that this is some woman he's just recently started dating.

Back when I was dating, if some guy I was casually seeing had called up a new guy to say, "Hey, did you know she's been sleeping with me too?" I would've been pissed.

What right would he have to deliver that news? I was a free agent and could date several people at once if I wanted. I felt no obligation to specifically disclose who else I was seeing at that early stage.

Now, if LW has reason to believe that the other woman is expecting monogamy - that this is what their agreement is - yet he's sneaking around behind her back, then telling her would be warranted. But so would dumping him because he's an lying cheat!

Somehow, I don't get the sense that's the case. I suspect he's a decent guy, and LW just wants the other woman to know that he's not totally committed to her yet, in hopes it'll ruin things in this early and fragile stage of dating. But if she tells, in some warped plan to keep him to herself, she'll likely lose him.

"I'm tempted to write her an anonymous note, telling her that I was here first, have been here a long time, and am continuing to have sex with her Lothario."

So, the decision point should arrive with the answer to this entertaining question:

Which of you has herpes?

That's what your guy will bring you. Eventually.

What the hell is the matter with women like this letter writer?

This guy clearly hasn't pledged monogamy to the letter writer or to the new one. He's dating for God's sake. The letter writer is clearly a booty call and she should be happy with that status.

Letter writer, I'm just guessing here but, have you ever noticed that he doesn't introduce you to any of his friends? He doesn't take you out to dinner very often? It's normally delivery chinese food, isn't it?

That's not to say that he doesn't like you. He does. Just not in a way that would actually involved you in his life.

You enjoy cock and he enjoys pussy. It's as simple as that. Know your role. Any attempt to intrude on his actual life is as inappropriate and small as it would be if he were to call up your father to discuss your orgasm habits.

This letter writer is way off base here. Do not, under any circumstances, contact this woman. That would make you a really, really crazy bitch in a lot of ways and you would lose so much self-respect and dignity that it would be impossible to put into words.

Like many people around the holidays, your thoughts turn to the have-nots: "Hi, I believe you have not heard that I'm having sex with your new boyfriend."

HaHa...great use of "have-nots."

LW, what Amy said. Since you don't like the fact that this guy is now seeing someone else, break things off with him. Don't send a note to this other woman.

What Amy said, and what Pirate Jo said. Exactly.

You already know this guy isn't going to work out long-term. Your anger/jealousy/whatever is misplaced. Sure, write her a letter (anonymous is for weaklings, though) but that's really not the issue now, is it? If you want a real relationship based on commitment and monogamy, it's YOUR fault for staying with this guy, who has clearly proven it's not going to happen, hasn't he?

This is about Posession. As in "You think you can get away from me? I will burn any bridge you try to cross." The LW is just two steps away from bed straps and sledgehammers so she needs to forget about the guy and the girl and ask herself why she let this relationship take her to this desperate place. What is it deep in herself that attracts her to this arrangement and put up with it. Hey the world is a big complex stressful place. You need a stable unyielding central compass to avoid getting tangled up. In this regard the LW has a lot of work to do on herself before she can truly work and play well with others