Tony's the boy we all wish we could save—his home life is pretty miserable, what with the religious parents who don't approve of him being gay. How can you not root for the teen whose parents don't accept him for who he is?
Tony's main purpose in Boy Meets Boy is to serve as a cautionary tale. Paul tells us,
I want a fair world. And in a fair world, Tony would shine. (1.57)
However, we don't learn much about his interests, outside of finding a boyfriend. Tony's a sympathetic character, and he's one of Paul's two best friends, but we don't really learn how exactly he would shine. We don't know what his interests are besides finding a boyfriend. That's fair, though—if you can't live your day-to-day life as your authentic self, you may be too focused on survival to explore your interests.
When Tony stands up to his parents, you'll probably be cheering. After all, it's what we—and Paul—have been waiting for him to do all along. He doesn't remind them straight up that he's gay, but he does say to his mom, "Paul is…my friend—nothing more, no different from Joni or Laura or any other girl" (24.154). Hey, you've got to start somewhere and this is the first step on Tony's road to becoming a self-actualized human being. We'll take it.