A little back story. Summer of last year, I was hanging out with a girl from my old high school. Thinking that I knew already, she told me a very descriptive story about how she and one of my friends girlfriends gave one of our other best friends oral sex late one night after a party. To add insult to injury, the girls boyfriend was passed out in the next room. This took place about 4 or 5 years ago and since then the girl and her boyfriend have continued dating, had a child together and gotten engaged. We have all continued being a close group of friends and neither the girl nor my friend that received the oral sex have made any attempt to come clean about the situation. Some things to weigh out are the fact that it could potentially break up a family & there is a risk of losing both friends if a.) my accused friend doesn't come clean b.) when told the unknowing friend may not believe that his girlfriend ever did this (they have been together for 7 years) or c.) that my unknowing friend will be upset that I haven't said anything up to this point. If the girl I was hanging out with that also took part in the late night escapades had not been there, only the other two parties would know and none of this would have came to light.