Originally published December 3, 2009:

I'm a longtime reader who thought I'd never have a reason to write since I'm universally known as the "good girl." I have a close male friend. Even though I knew he was dating someone else, we became friends-with-benefits several years ago. Because of his relationship (and the fact that he lives with her!), sometimes it felt like a booty call; other times, it felt like it was leading to something more. He once admitted that if things were different, he could see us together. But a while ago I discovered that while he was unfaithful to her, he had also been unfaithful to me.

On to the point: He recently proposed to his girlfriend. I'm happy for him if it's what he truly wants, but I feel like he did it out of desperation. All I know is that there were some ultimatums involved. Here is my dilemma: I don't want to out myself, I don't want to hurt him, and I don't want to ruin our friendship, Dan, but I feel like she has to know what her fiancé is really like before they get married. Should I anonymously contact her and let her know that her man is a cheating man-whore? Thanks!

One Of Many Other Women

My response after the jump...

Gee... it must have come as a real shock when you realized that a man who was capable of cheating on his live-in girlfriend was also capable of cheating on the girl with whom he was cheating on his live-in girlfriend. No one could've predicted, huh?

On to your question: I hate to think of some poor woman marrying a cheating piece of shit (CPOS)—a CPOS is not to be confused with an honest nonmonogamous dude (HND)—in ignorance of his cheating-piece-of-shit-ness. It's possible that the CPOS's fiancée already knows and has forgiven him; perhaps one of those ultimatums touched on cheating. But odds are better that this woman doesn't know, and someone really ought to clue her in before the wedding. But should that person be you?

I'm not comfortable with your motives, OOMOW. You may be known throughout the universe as a "good girl"—as the good girl—but your actions prove that you're something of a "bad girl." And there's more: Your desire to destroy your FWB's relationship proves that you're something of a "vindictive girl," your attempt to pass your vindictiveness off as concern for a woman you've repeatedly wronged proves that you're a "self-deluding girl," and your desire to accomplish all of this without paying any price yourself—you don't want to out yourself or risk ruining your "friendship" with the CPOS—proves that you're a "selfish girl" and a "cowardly girl."

Come on, OOMOW: The reason you want to do this anonymously is because your top concern is having the CPOS all to yourself, and that means sticking a knife in his current relationship without leaving any fingerprints. So it's a good thing—a useful thing—that you weren't the only "other woman" in his life, OOMOW, because he'll never know for sure which one of his other women ratted him out.

Setting your highly suspect motives aside...

If I were in the fiancée's shoes, I would want to know what was going on before the wedding. So I do think you should tell her. But if you have any shred of decency—even the tiniest bit—you will tell her personally, apologize profusely, and provide her with some proof. An anonymous tip won't cut it: A CPOS who has successfully hidden a collection of other women from his fiancée will be able to talk his way out of an anonymous accusation of infidelity. He'll either claim the e-mail was sent by a vindictive ex-girlfriend of his, which has the benefit of being very nearly true, or he'll claim that an ex-boyfriend of hers is trying to destroy her happiness.

Finally, OOMOW, why do you want to be with the CPOS? He cheated on his fiancée, he cheated on you, and he probably cheated on the women who he was cheating on the both of you with. He's a piece of shit, his fiancée is a fool, and you're a vindictive, self-deluding, selfish coward. I'm not sure if you can all do better, or that any of you deserve better, but I do think you should all try.