Adult Joke: Making love to a girl in the back seat of a car

A guy on a date parks and gets the girl in the back seat and they make love.

The girl wants it again and the guy obliges her. She wants more and
they do it again. She still wants more and the guy, by now exhausted, says:

"Excuse me a minute I have to relive myself."

While out of the car he notices a guy a half block away changing a
flat. He goes up to the guy and says;

"Look, I've got this gal in my car and I've given it to her four or
five times and she still wants more. I'll change your flat if you'll
take over for me."

The guy agrees. He jumps into the back of the car and starts to go at
it with the woman.

He's just getting to the gravy strokes when a cop knocks on the
window and shines a light on them.

The cop asks, "What're you doing in there?"

The guy says "I'm making love to my wife."

The cop asks, "Why don't you do that at home?"

The guy answers "To tell you the truth, I didn't know it was my wife
until you shined the light on her.