Three labradors, one black, one brown and one white, are sitting in the vet's waiting room waiting for their appointments. The black labrador asks the brown one why he is there.
"I have a problem with other dogs", replies the brown labrador, "it doesn't seem to matter if it's male or female, I have to hump it. My master is fed up with me and I am going to be castrated".
"That's awful", says the black labrador, "and why are you here?" he asks the white labrador.
"I can't resist human legs", he replies, "I have to hump their legs whenever they sit down. Yesterday I humped the vicar's leg and my master was very embarassed, so he has sent me to be castrated too".
At this point the brown labrador asks the black labrador why he is waiting.
"Well", says the black labrador, "yesterday I walked into my mistress's bathroom just as she was coming out of the shower. She accidentally dropped her towel and bent over to pick it up. It was too much for me and I am sure you can guess what I did".
"You bad dog!", exclaims the brown labrador, "so are you here to be castrated too?"
"Oh no!" replies the black labrador, "I'm here to have my nails clipped!"