There's none. They both knock on the door, but never goes in!
Someone knocking at your door for no apparent reason.
Islams It.
Princess Diana wouldn't be caught dead in a Volvo
One's a prime number, the other's a prime minister.
Resisting a rest.
Knock on the door.
Jehovah's citruses.
Ding Dong
Because they don't like random people knocking on their doors
A Jehovah's Witness.
Test tickles