My brother's rude, manipulative, 16-year-old girlfriend is staying at the house and refuses to leave, because of supposed "family problems" at home; she's been here a fucking week already. Me and my brother share a bedroom, we don't have the space for this bullshit. plus, this girl doesn't even go to school either, she refuses. Quick, guys, I need efficient ways to get her out of the house, to make her want to fucking leave.

My brother's girlfriend has been staying at our house as well. He's in bootcamp so she's here everyday. Kind of annoying at times, but I've put up with much worse. We don't have to share rooms so it isn't a problem for me.
The nerd fest thing might work. Some friends came over and we hung out in my brother's room and she almost left the whole house.
My goal wasn't to evict her so if you put a little effort into this approach you should be able to get her to leave.
-What kind of music is she into? You could always play something extremely obnoxious.
-Could always just start masturbating.
-Spill chips somewhere in the room to attract ants n' shit.
-Your name is The Butt....Do Butt things. (e.g. fart at her, fart on her, etc.)
-Throw silverware at her.
-Stand naked in the corner. Do not blink.
-Kill it with fire.
-Kill it with water.
-Kill it with something else.
-Give her Cancer.
-Ask her about her anus.
-Whiten her nose for Satan.
-Whiten your nose for Satan.
-Satan.
-Rape objects in your room while wearing chains and whistling.
-Fill the room with bees.
-Sit on your brothers bed.
Accidentally shit your pants.
-Make her
your girlfriend. Then keep your pimp hand strong.
-Rape your family members. This would create "family problems"(The reason she left her house) at
your house.
-Rape her and your family. "Family problems" + Rape = Double Whammy.
Just brainstorming here....
Oh, and if there's a bathroom above your room, flood it.