"Hooker on the Boardwalk" joke

A guy's walking down the boardwalk in Atlantic City and he runs into a hooker.

He says, "How much?"

She says "Twenty bucks." He says, "All right."

They climb down under the boardwalk, and he bangs her.

The next night, he runs into the same hooker, they go under the boardwalk, only this time while he's banging her, she blasts two incredible farts.

When they get done, he hands her twenty-five dollars.

She says, "What's the extra five?"

He says, "That's for blowing the sand off my balls."