Two porn stars, a man and a woman, are going at it during a shoot. They're doing it doggy style, and the director keeps urging them to do it faster, since they're in sort of a homestretch two-shot. So they're really going at it, and the woman kind of looks over her shoulder at the man and says, "Ooh, you feel so good inside me!" And the man thinks to himself, I choose to believe you.