I think it's a Bang bros video.

From what I remember of this video, they're in a van driving around. They "pick up" this girl for the guy's birthday. After getting head, the guy goes to fuck her and at first she says no she can't and slightly pushes him away before he continues and she just gives in.

At the end, when he blows his load on her, she looks away from the camera almost as if she's a bit embarrassed by it.