Q: What did the peanut butter say to the bread?
A: Quit loafing around!

Explanation: When you grind up peanuts, you get peanut butter.  Bread that you buy at the grocery store, in the United States, mostly comes in a loaf; it is called a loaf of bread.  Loafing around means to be lazy and not do anything.

This joke is funny for a few reasons: first, it is funny because the peanut butter is talking; second, it is funny because the peanut butter is telling the bread, a loaf of bread, to stop loafing around, stop just sitting there.  This joke is playing with the word loaf.

Come back tomorrow to see how the bread responds!