A man walks into a chemist and says to the bloke behind the counter, Listen, I have three girls coming over tonight.

I've never had three girls at once, and I need something to keep me horny... keep me potent. 

The bloke reaches under the counter, unlocks the bottom drawer and takes out a small cardboard box marked with the label Viagra Extra Strength and says, Here, if you take this, you'll go NUTS for 12 hours!

The man says, gimme 3 boxes 

The next day the man walks into the same chemist, right up to the same bloke and pulls down his pants. The pharmacist looks in horror as he notices the man's willy is black and blue, and the skin is hanging off in some places.

The man says, gimme a tube of Deep Heat.

The bloke replies, DEEP HEAT?? You're not going to put Deep Heat on that are you?

The man says, No, it's for my arms. The girls didn't show up.