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 guy 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'