A Funny Sex Joke from http://www.jokesbee.com/adult/index.html:
WHAT SIZE?
A young man went into a sex shop to buy some condoms and a sales girl approached him…
Sales girl: “Can I help you, Sir?”
Young man: “Yes, I want to buy some condoms.”
Sales girl: “What size do you need, Sir?”
Young man: “I didn’t realize they came in different sizes. I don’t know what size I would need.”
Sales girl: “May I hold your penis to tell what size you would need?”
As she was holding the penis, she called for assistance:
“Give me a SMALL one…”
“Wait! Make it MEDIUM…”
“Wait! Make it LARGE…”
“Shit! Give me a TISSUE !!!”