Thanks Derby, that's good advice.
Vincenzo I can see why you'd get that impression from what I said, but it's really not like that. She was basically forced out of her previous living situation for coming out as poly. She hadn't gotten her student aid check so she was going to have to pawn all her stuff to stay in a hotel while she looked for a place. Now she's got her money, she felt really guilty about imposing on me and has been paying me back by buying me meals and stuff.
The place she's staying now, she is renting her own room - just happens this guy who is now her roommate is also someone she's hooking up with. Still your advice is well taken and I'm trying not to take our relationship too seriously.