A man goes to a sperm bank and says, "I'd like to make a deposit please."
The doctor says, "Go and fill this up," and gives the man a bottle.
Three days later the man returns to the sperm bank, marches into the doctor's office and says, "I've tried with my left hand and tried with my right hand. My wife has tried with her left hand and her right hand. My mother-in-law has tried with a rubber glove on and even took her teeth out and tried with her mouth -- NONE OF US CAN GET THE TOP OFF THAT BOTTLE!"