Don't wanna be a dick

I'm out in my high school (though I don't pass for anything except a butch lesbian) and the drumline I march with has been really supportive! They always make sure to use my correct name and pronouns- except this one guy. He's the only one who uses my birth name without apologizing and/or fixing it and I never want to correct him because I hate him (he has no work ethic and isn't improving as fast as everyone else as a result) and so I don't want to be a dick to him