So I'm not all that bad at the first stages, and whether it's pickup game or not, I often find myself in a situation when it's pretty clear that she's into me and everything, but I'm really bad at making that final move. Here's an example that has happened more times than I care to admit:

We're at my place, in my room, talking, listening to music, I'm showing her some video game, whatever it is. She's in to it, I'm in to it, it could go down at any second. Except I don't ever know how to make that transition, and the night goes on and eventually it's late and she leaves or something. Short of blurting out awkwardly, "WELL, WANNA HAVE SEX NOW?" Which, I don't really wanna do, obviously. I guess I just have no model for how this happens in a typical scenario. Help a brother out with some tips or examples?