hey mugs, if it makes u feel any better - i went through a similar situation. One fine day about a year ago, I found out that my bf of 2 years whom I loved dearly has slept with my bestfriend and roomate in college of 4 yrs!!!!! and not just once either. and they had lied to my face for 2 fucking years about it. U can imagine my shock and disgust. It was one thing if he had slept with some strange girl, but to sleep with my bestfriend?????????? and the bestfriend, she turned out to be this evil bitch ( I never saw it before cuz I cared for her and only saw the good things). ANYWAYZ, so ofcourse I immediately dumped his ass and tried to kick her out of my dorm room (that's a whole other story). It was really painful because I loved both of them so much, and I wanted to be their friends still. But u have to do it, there's no point hanging on especially when u havent done anything wrong. If your x-gf really cares, she will come around and earn your forgiveness. To end this story, I dont know what happened to my bestfriend, but my x-bf wrote to me a month or so ago wondering how I was. He realized the dick that he was and also how much fun we used to have together. We are now trying to be friends again. I dont know if that is smart - but time heals all wounds, so if it works great - if it doesnt - his loss.