First off, Luckystar, I swear if you and Asterisk had been standing in front of me just now I would have probably knocked you on your ass, assuming you are not in fact a woman, in which case I would have cursed you out at the top of my lungs. I get it, it's a joke, HAH HAH 'tis to laugh, but that's disgusting on its own, not to mention the fact that SHE'S. A. CHILD. Okay, teen, whatever, but to someone my age, yes, A CHILD. And she's clearly not comfortable with it either, so double the asshattery points to you.
TLDR: I suggest you apologize for being a creep, however unintentional. Go ahead. I'll wait.