Here's a solution for you. You'll need a bit of space between the bed and your wall for this to work, but if you put the camera on a crane you could operate it while you're fucking the girl. There's a counter-weight that goes on the other end that's meant to make the camera "fly" but this would be perfect for your situation because it will allow you to raise and lower it smoothly without it getting in your way. And you won't have to hand-hold the camera.
There's a bunch of them on the market, but here's what one of them looks like.
http://www.adorama.com/CAM99133050.html