The only student I'm really having a real issue with this year, is sadly enough, one of my best students, meaning that he gets straight A's completes all of his work, etc. The only problem is that he has a sh1tty attitude, especially about me. I think it started when I gave him a warning for speaking up without raising his hand. Ever since then, even when I pulled him aside to talk about it to try and clear up any misunderstanding, he's been muttering things about me below his breath, trying to toe the line of misbehavior giving me side-glares to make sure I'm not catching him, etc. When he realizes that I'm watching him he just resorts to muttering and complaining about me under his breath to his partner, who is starting to get sick of it, because his entire group enjoys being in my classroom, and he is the only one who doesn't seem to. I can tell that for years he's probably been a teachers pet, and used to getting his way. Because he is so intelligent, he knows just how much he can get away with without getting into trouble (I don't really have a rule about students muttering bad things about me under their breath, especially since I can't even verify that they're saying bad things about me since I can't hear it really). He's just made it very clear that he doesn't like me and he's going to show displeasure for about everything I do. I've ignored most everything from him so far, because hey, an 8th grader feels like he needs to act out to get my attention, big whoop. But his disrespect is starting to become more audible (I'm almost catching what he is saying), and I'm afraid his attitude will spread through the classroom, even though at the moment everyone seems to turn a deaf ear to it. Because he is popular, the other students seem to just laugh along with his snide remarks and superficially agree, but I can tell that they really enjoy the classroom. How would you guys deal with this?