"A Hundred Bucks Each" joke

A guy goes over to his friend's house, rings the bell, and the wife answers.
"Hi, is Hank home?" he asks.
"No, I'm sorry, he's out running some errands," she replies.
"Would you mind if I wait?" he asks.
"No, that would be fine. Come on in," she says.
They go into the kitchen, sit down, and the guy says, "You know, Laura, you have the most beautiful breasts I've ever seen. I'll give you a hundred bucks if I could just see one."
Laura thinks about it for a second and figures what the heck. She opens her robe and lets him see one. He promptly thanks her and throws a hundred bucks on the table.
They sit a while longer and Ben says, "They really are so beautiful. I just have to see both of them. I'll give you another hundred bucks if I could just see both of them together."
Laura thinks about it and figures what the heck. She opens her robe and gives Ben a nice long look. He thanks her, throws another hundred bucks on the table and says, "I really can't wait any longer. Please tell Hank I stopped by," and leaves.
A short while later, Hank arrives home and Laura greets him at the door. "Your friend Ben stopped by to see you," she says.
Hanks thinks for a moment and asks, "Did he happen to drop off the two hundred bucks he owes me?"