There is nothing wrong with the fact you are gay. The fact you know you're gay and have continued to string your girlfriend along, the fact you have been cheating on her for months and the fact you are even planning this however is wrong and makes you a awful person. The fact you will never see any of these people again isn't the point (and not necessarily true). You are deliberately choosing to humiliate your girlfriend in public for no reason (you haven't even said one bad thing about her in the thread) other than because you can. That choice makes you a horrid person. Also have you been having sex with your girlfriend during this time as well? Imagine how you would feel if someone did this to you. Heck just imagine how awful you would feel if one of these things happened to you - say a cheating partner. Now imagine that but it coming out in the most horrendous fashion deliberately because your partner not only had not respected you enough to be loyal to you but chose to reveal it in this manner. Plus you will likely put the whole prom in a negative light and I would hope a lot of people wouldn't be supporting you, but angry. You won't be cheered away, you will be talked about as the cheating loser who humiliated his girlfriend in public for no reason and ruined everyones prom. The ONLY good thing in this thread is you mentioned some concern for your girlfriends A-Levels. Just wait until her exams are over and tell her in private whilst trying to care about her feelings.