My College Girlfriend Was Right To Be Paranoid (M/F)

I was a quiet kid in high school, I had friends and what not but I was still quiet so I sometimes got overlooked in the dating scene. I decided to change that in college and within 2 months got a girlfriend.

We dated for about 5 months, during that time I have a friend I'll call Maria who I start to really hang out with in the twilight era of my Freshman relationship. She's there for me during all the fights and there for me during the break up. In fact part of the reason the break up happens is because my girlfriend thought I was "uncomfortably close" with her.

Well either way relationship ends and Maria listens to my post-break up whining. However one night while we're sitting in the abandoned dorm lounge things get really flirty. Lots of play punching and what not. Eventually it comes to a head when I make a joke inferring that she's a guy. She scoffs and looks me in the eyes and says "I'm a girl, trust me, don't you believe me?" when she does this she opens her legs slightly but not overtly.