If you feel that his ‘playing around’ is actually just a way for him to express hostile feelings, you should talk about it and tell him to stop. Are his comments limited to gay-related epithets, or does he also call you ‘dumbass,’ for example (as my friends and I often did at your age)? If you think he really is just joking around, you might want to let it go, unless it makes you too uncomfortable to talk to him. In this case, I would couch your request in a joke by saying something like, ‘your ugly straight ass isn’t allowed to call me that, bitch.’ (Or something that doesn’t make you sound as old as me!) I lost some people that I thought were ‘friends’ when I came out. Others remain my friends, but they avoid mentioning anything about it or acknowledging it. Given the choice, I’d prefer a straight friend who jokingly called me a fag.