(Throwaway account since friends know my Reddit username, names changed.) I was taking a trip to Canada this weekend with my school, which had my best friend Helen, her best friend Kate, and this guy named Jake. Just to preface, I’m a single gay guy. One night, Jake asked to sleep in my room because his roommate was really sick and they slept in one bed, so I agreed.  So he came into the room and we slept opposite sides of the bed. But he then initiated touch and soon enough, we hooked up (like making out and cuddling, not anything further). 

Later that week, Helen told me that he and Kate have been dating for about half a year, which I didn’t know about at all. I also thought he was straight until we hooked up and now I don’t know what to think. I later saw them cuddling while watching a movie during the trip. I talked to Jake afterward and we said that everything was cool, never to talk about again. But now thinking about it, I’m unsure. Am I the asshole if I don’t say anything about him cheating to Kate?