Old but classic-----
A 6 year old and a 4 year old are upstairs in their bedroom. "You know what?" says the 6 year old. "I think it's about time we start cussing".
The 4 year old nods his head in approval. The 6 year old continues.
"When we go downstairs for breakfast, I'm going to say "hell" and you say "ass".
"OK!", the 4 year old agrees with enthusiasm.
Their mother walks into the kitchen and asks the 6 year old what he wants for breakfast.
"Aw, hell, mom, I guess I'll have some Cheerios."
Whack! He flies out of his chair, slides across the kitchen floor, gets up, and runs upstairs crying his eyes out, with his mother in hot pursuit, slapping his rear every step. The mom locks him in his room & shouts, "You can just stay there till I let you out!"
She then comes back downstairs, looks at the 4 year old , and asks with a stern voice, "And what do YOU want for breakfast young man?
"I don't know," he blubbers, "But you can bet your fat ass it won't be Cheerios!"