Why do some guys do this on a date?

Setting: The lobby of a movie theater

Characters: A man and a woman wait. They are on their second date.

Exposition: The pair arrive early for a movie and decide to wait in the lobby and eat some popcorn. The man is on-call and must have his phone turned on during the film.

Dialogue:

Man: "Oh, I should set my phone to vibrate."
Woman: "That's a good idea."
Man: [Turns his phone to vibrate and puts it in his pocket. Smiles luridly and says:] "I lodged it up next to my sensitive bits."
Woman Thinking: [I will never go out with him again.]