Dude, if she has a bad attitude, why would you even want her to begin with? You can't even assume she's straight: maybe she's so disgruntled with all the guys hitting on her (or stemming from some sort of trauma relating to her attractiveness).
I would think of his teases as exactly that, teases and nothing more until you do something on YOUR end that definitively points out whether she likes you or not. This isn't middle school, with "Do you like me?" notes and whatnot.
Now, it's not even fair perhaps to assume that it is true that she has a bad attitude. Maybe she reacted in blunt ways to unsolicited, maybe even gross advances. Point is, find out for yourself.
Because we have to chase him. Because he's the hero Gotham deserves, but not the one it needs right now. So we'll hunt him. Because he can take it. Because he's not our hero. He's a silent guardian, a watchful protector. A dark knight.