I've only got one friend in bed and this is the article that really helped me. Follow those steps and NEVER tell her how you feel.
http://www.sosuave.com/articles/escaping.htm
I've have several other opportunities with friends who hit on me, got me drunk and dragged me or invited me to bed with them etc I know I could have banged, that weren't very attractive and one that other that was and was engaged. I just flat out didn't go through with that but basically what I found was I did the exact steps just not premeditated.
Looking back basically every good female friend I have had I could have fucked. Thing is most werent attractive or worth messing it up, so not sure what that says really. The 1 that was I messed up for a while just because I was still a needy chode, be careful you'll reak of it. You really need to disappear for a couple months start getting other girls come back with a better mindset and game or you might end up like I did.