I'm not sure what the red pill line of thought is in dealing with chicks with boyfriends, so I'm hoping you guys can enlighten me. I'll try to keep this as short and simple as possible.

I'm a university student and I share a house with a female friend of mine (and 4 others). She's hot; a guy with a dick would bang her. I know for a fact that she has always liked me (from friends, IOIs, etc.), but when I first met her it was a rule of mine to never do anything with a 'slut' (for lack of a better word) - her high partner count to age ratio. Interest cooled off as I made myself unavailable. But now I don't care. We like our sluts, right?

She has been with her boyfriend (not at the same university) for just over a year now, but having recently returned from the Christmas break she has suddenly become overtly sexual towards me and very, very forward. This has come out of nowhere. I'm talking about biting me, offering to give me massages/play with my hair, asks me to bench/squat her, to play fight (every freaking day), texts me constantly throughout the day and late at night. None of this has happened before. She came to my room after a night out and slept in my bed... you get the point? I do my own thing back and this is the most sexual I've gotten with a chick without actually banging her. I'm walking around all day full mast and I know it's just a matter of time before I go in for a smooch. If this was just some random club bitch I just met I'd have already banged her by now, but she's not. I've known her for a year and a half now and our rooms are next to each other... and she has a boyfriend. I couldn't give a shit about upsetting the dynamic of the household by banging a housemate, but what's holding me back is this boyfriend. I can't bring myself to make a move because I know she has a boyfriend. And I can't get my head around the fact that she has suddenly started to act this way to me when she's with someone. Immediately following our play fight/fooling around/just insane flirting earlier today, she texts me when we're in our rooms and out of nowhere tells me that her boyfriend is coming up today so I better not mention anything about our play fighting and her bruises/marks (that's how rough it gets). As I'm typing this, I can hear them banging in the room next door. I feel like a cuck and we've never even banged.

So, /r/asktrp, how do I proceed? Is she playing me like a fiddle, fucking with my head? If she continues to act this way with me after her boyfriend returns home, should I just make a move and let the cards fall where they may? After all, I'm single. She has the boyfriend. The onus is her. Or should I not reciprocate and leave her be? Any advice would be helpful, really. It's driving me mad.