I heard a great joke today: 
A seven year old boy and his four year old brother are upstairs in their bedroom. The seven year old is explaining that it is high time that the two of them begin swearing. When his little brother responds enthusiastically, the seven year old says, "When we go down stairs for breakfast this morning, I'll say "Hell" and you say "ass." The four year old happily agrees.

As the two boys are seating themselves at the breakfast table, their Mother walks in and asks her older son what he would like to eat for breakfast. 

The seven year old replies, "Ah hell, mom, I'll just have some Cheerios."

Pop! The surprised mother reacts quickly with a reprimand. The boy runs upstairs, bawling and rubbing his behind. 

With a sterner voice, the mother then asks the younger son, "And what would YOU like for breakfast?" 

"I don't know," the four year old blubbers, "but you can bet your ass it's not gonna be Cheerios."