She's already your GF, just go for it. let your hands wander a bit during your next smoochy session (just make sure it's on the couch/bed, not at the door on her way out... fail)
Chances are, she's just as curious when you're going to do the humpty as you are. Girls aren't as innocent as they pretend to be, and they certainly think about sex at least once every 10 minutes compared to a guy's 3 per minute
(statistics were made up on the spot, I claim no accuracy)
edit: if you're not interested in the sex thing yet, well, sounds like you're already covered, though you should really grow past the pinch/poke high school games. Time to be an old fart like the rest of us.