girlfriend's past (yet still somewhat related to the present)

So, to make a long story short, my girlfriend had sex with a friend of mine (a friend of mine who has a girlfriend of 3+ years) shortly before we started dating. She didn't know he had a girlfriend at the time, and I was physically at the party they hooked up at (although I didn't know about it until recently.) We've been together 9 months or so.

It's been about 3 months since I found this out (She told me about it after I drunkingly made a joke about her making out with him). Since then, I've been kind of an asshole about it, to be honest. I really let it all out at one point and tried to make her feel like a bad person. Not only because she slept with a guy she barely knew, but because we had been really good friends with this couple (the guy she slept with and his girlfriend) up until the point I found out about it. She even invited them over to a party she was having literally a week after it happened.

To her credit, she has done a lot of things right. She didn't lie to me about it happening. All signs point to her being completely truthful about that and everything else. Plus, the relationship is easily the best one I've ever been in. I'm 27, so I've had time to be in a decent amount of relationships. In addition, she stopped hanging out with the guy and/or couple in question after she knew it would upset me if she did.

Also, just to throw this in there, I'm also not of the "sex outside of a committed relationship is a crime" variety. I've had sex outside of a committed relationship.

Two questions:

1)Who's the asshole here, me or her? Is it my own issues that are preventing me from getting over this, or is there something real here I should be worried about?

2)Should I tell my (ex)friend's girlfriend that he's a lying douchebag?

.

Firstly, she was not in a committed relationship with you when it happened, so you should not have been an asshole to her about it. Also she did not know he had girlfriend. The moral judgment of her sleeping with a guy she did not know - that is another opinion, and I am not here to judge anyone. In answer to your question numbered 1, I think your are projecting your past experience of sleeping with someone while you were in a committed relationship onto to her. Not fair. She did not do it when you were together. Answer to question numbered 2. He is an ex friend - so what is it going to acheive?
She seems to be making all the effort to stay away from them. I think you need to work on your guilt of your past mistake, or you may loose a good relationship.

Dude, having sex with someone else , outside of a committed relationship is cheating, pure and simple. You are in the wrong here, you are a past cheater and she isn't. She did not know that the guy was in a relationship , when she slept with him, so there is no foul on her part. Get your act together, or she's going to dump you for being a jerk.

Does anyone remember the other thread where this dudes gf screwed some dude in the bathroom. The dude had a gf and she was single. Everyone is now one big happy group or friends.

The answeres were completely different.

Anyways mine stays the same. You're a dink. She was single. She didn't screw up- the dude did. Should you rat him out? Ahhh I don't know that's a tough one. Though you are meddeling. You didn't even do the sleeping around. And you do just pull the curtain on your gf too if you do tell.

Just to clarify, i've never cheated on anyone. The "I don't think sex outside of a committed relationship is a crime" thing didn't mean that I think it's ok to have sex with someone else while in a committed relationship. It means that I don't necessarily morally judge people who are both single and have sex with each other.

"I've had sex outside of committed relationships" means that I've had sex with people I've not been in a committed relationship with while I'm single. It doesn't mean I was in a committed relationship at the time.

I understand that the wording was confusing.

If you have to ask who the asshole is, it's you.