How about limericks with FUCK in them...
There was a young man of Ostend
Whose wife caught him fucking her friend.
"It's no use, my duck,
Interrupting our fuck,
For I'm damned if I draw till I spend."
There was a young person of Kent
Who was famous wherever he went.
All the way through a fuck
He would quack like a duck,
And he crowed like a cock when he spent.