During the 3rd month of our relationship, i was at work on a friday night. One of our male friend called my girlfriend and asked her to come to his birthday party at a bar. She went for about an hour and said her goodbyes. Birthday boy suggested he walk her to her car. Not sure what happened in the bar and not sure what occurred during this short walk to her car but they ended up making out. Girlfriend told me this like 2 months after it happened during an argument. According to her they kissed on the way to her car and made out in the car. Whole thing lasted less than 10 minutes. 10 minutes, i find that hard to believe. This birthday boy was suppose to be my friend. 2 months went by and i didnt know of it. The whole time these 2 been acting like nothing ever happened. My girlfriend and him still hangout every now and then. If it happened once, it can happen again. I just dont trust her anymore. She claims it was just the heat of the moment. I feel like im in a love triangle. She claims they are nothing but friends. Friends dont kiss. I know she is special. Hard to find a girl like her. We have been dating for about a year now.