Two guys in doctor's waiting room.
1st guy, 'Hi there Joe. What are you sseing the Doc about?'
Joe, embarrassed, 'I've only got one testicle. I'm getting married and I want to know if I can father children.'
1st guy, 'Oh, that's nothing to worry about. You'll be fine. I know a few guys who only have one testicle, and it's never stopped them fathering kids. As a matter of fact my cousin has odd-shaped testicles and he's got six kids.'
Joe, intrigued, 'Odd-shaped testicles? Really?'
1st guy, 'Yeah, one's small and cube-shaped like a dice, and one's big and round like a pool ball.' He becomes thoughtfull before adding, 'The other three are perfect.'