I don't know. I wouldn't. But that's just me. I dated a girl for a short while about a year ago. Fell in love head over heels. She cheated with an ex while we were mutually exclusive, it happened only once. I went through the same reasoning you're going through. I let her chase me, stroke my ego, thought it would be just sex, I had no more feelings for her. Wrong. In the end I didn't sleep with her again, and I'm glad. She doesn't deserve to even look at me. I know she's not a bad person, I really know that, deep in my heart. But fuck that bitch! She did what she did, the consequence is looking at this piece of fine ass knowing it will never be hers again. She still contacts me nowadays, misses our talks, well she could have thought about it earlier. I know this sounds revengeful etc. I don't blame her anymore, but this behavior doesn't live up to my standards. I'm not a moralizer, did some bad things in my time, got some points for hell, not cheating though, but it's irrelevant. What I mean, I know this is one of the most hurtful things a person can do. I always tell my gf, if it was a slip up and you used protection I don't wanna know. It hurts, it makes you feel less. If I did that to a girl, I'd either not tell her if it was previously agreed so, or I'd break up with her with a different excuse and never sleep with her again. Why would I crush someone's self-respect, dignity and self-confidence, whom I supposedly love? This is the standard I expect from girls I date. She broke it. I would throw away my dignity and my standards if I slept with her again.
The point is this, it's not about teaching her a lesson, it's about teaching yourself that you don't go and walk over your dignity. Fuck pride. It hurts, sure. It doesn't matter what she will think, it matters how much of your dignity in your eyes you give up by sleeping with her again. There are million other chicks, some of them on the same floor of your dorm, so you don't even have to take the stairs
CHAT
