You can hurt someone every time you make a gay joke. Let's say you're a football jock. It might be your friend, who makes up his mind never to come out to you and trust you. It might be your bisexual girlfriend, who's afraid of being dumped. It might be the kid who looks up to you, who first gets the idea that being gay is wrong from you, and goes home depressed or ready to pick on more kids. It might even be the guy you called a fag. Maybe he is gay, or maybe everyone thinks he is, and that was the last straw for a troubled teen.
Even if you're alone with your friend who makes plenty gay jokes himself, or who has a girlfriend, you never know who's just in denial.
By the same token, standing up against the teasing could be what saves someone's life. It could be what makes your friend or girlfriend trust you, or makes the kid who looks up to you be okay with it. It could even be your brother or sister who hears about it, and trusts you first.
If only it were that easy. If only it wasn't hours later that I come up with the perfect response. If only I could be sure that was what you said. If only I could be brilliant and end the jokes without being rude or just making it worse. If only I were braver.
I have the Broadway song Defying Gravity from Wicked in my head, which brings the phrase "it comes at much too high a cost" to mind when thinking about teasing. Even simple, unassuming comments.