I feel really horrible. my friend and his gf and I were all watching some TV in his house I went to grab more cheetos in the kitchen while his gf was in the bathroom (the bathroom and the kitchen are in the same general big room). and as soon as I'm done pouring the bowl she opens the bathroom door and asks if I can "help her with something" I didn't know what was going on but i said what and walked over to her and she just grabed my private and pushed me into the bathroom and undid her cloths. We had sex for only like 1 min and I went into the sink because it was a big surprise and I didn't realize what was going on. I really do feel bad afterwards because we were all sitting on the couch after we did it and my friend was oblivious. she has been his gf for around 5 years too. Don't know why i'm telling you people i guess just to let out what i've been keeping inside for a while.

 oh and his gf keeps on trying to call me.

what s your advice?