I'm watching a scene as though on television, featuring Madonna (the dance pop star, not the religious icon) on a stage, under a spotlight. The area around her is dark, and she lies on her back with her knees up and spread. She pulls her knees together and apart, quickly, repeatedly. I think that it is only my own perception that makes this position seem sexual, but as the camera pans, it zooms in on her crotch, and I realize that the impression is intentional.

As the camera gets closer, it becomes apparent that "she" actually has a phallus, and it slaps up and down against her belly as she pumps her thighs. As the shot gives a closer look, we can see "her" wearing a condom. I think it's some sort of advertisement.