A man and his girlfriend are having a sexual encounter. He asks her to “go downtown” so, with a sigh, she gets on her knees in front of him and starts peering at his genitals, looking and tipping her head this way and that, studying the whole business.
After a couple minutes of this, he asked her in a sort of peeved voice “Well, what the fuck are you doing?”
She said “I’m doing what I always do when I’m downtown with no money…. just looking.”