Condom joke

A grandpa walks into a grandson's apartment and sees a condom on the table. "What's this!?" demands the grandfather.
"It's a condom," replies the grandson sheepishly.
"What do you use it for?" asks Gramps.
The grandson is surprised that his grandpa really doesn't know what a condom is, and replies, "I use it to keep my cigarettes dry when I smoke in the rain."
To his surprise his grandpa says, "That's a great idea," and goes off to the drug store. He asks the pharmacist for a condom.
"What size would you like?" asks the pharmacist.
"Oh, big enough to fit a camel."