Sebastian knows that he should probably leave his high school time behind, and just let it go by now, but he has always been known for being childish, so he can't really help it. He is pretty much used to getting things his own way, and he doesn't like it when he doesn't, so even if it is quite some time since he last saw Kurt, then he is not one to let go of a grudge. He has never done it before, and he is not about to start doing it now.