"I mean, you're the one who's trying to pick the fight... I'm not interested. Mostly because I'm not gonna be the one running home crying." He has magic and combat training on his side and this guy just-- seems to have a lot of bad attitude and obnoxiousness.

No matter how much that bitter part of Billy wants to give in and punch the guy, the more mature part of him is gnawing t him to not pick fights with dumbass teenagers. Especially when Billy's trying to give the benefit of the doubt here and assume he's probably not just an asshole and maybe he's defensive for other reasons.

Besides, looking at him straight on -- he's got a kind of familiar face. "Why don't you just calm down a little? Alienating yourself around here's not really a good idea, just saying."