Working graveyard is not fun. Hi! I'm Natasha and I have three characters:
Mordecai Roberts (Chrestomanci - this journal). He's not a stranger to shady people or activities. He's trying to be good, but I wouldn't be opposed to a bad influence on him. Vala is free to flirt with him. He'll flirt back. He's as easy going as they come, so he probably won't be easily upset, but please beat him at poker. He's terrible with money to begin with, though, so Vala will probably won't win much.
Edmund Pevensie (Chronicles of Narnia - justed). He won't be up for shenanigans, but flirt with him, try to rile him up. He doesn't lose his temper easily with people he doesn't know and he has no clue how to flirt, but it's possible to annoy him quite a bit and flirting will amuse me. Ed's been around for a couple of years now.
Marcus Cole (Babylon 5 - fortheone). He won't necessarily help with shenanigans, but he won't interfere, either, unless he sees a reason. He's a bit of a troll when he decides he likes someone. He doesn't have much to steal, so taking what he has would annoy him since it's personal. He's easier than Mordecai to rile up, but harder than Ed. He has a couple of very specific berserk buttons, but you have to know them, generally.