Q: Why did the kids fire their squirt guns into the air on that windy day?
A: They were just shooting the breeze!
Explanation: A squirt gun shoots a stream of water, much like a spray bottle, but in the form of a gun. Many people like to play by squirting water at their friends on a warm day outside. Some people train their pets by squirting water at them (others say that squirting animals does not work or is mean).
A breeze is wind that blows just a little bit. To shoot the breeze is an idiom that means to talk with your friends about nothing really important.
This joke is funny because it plays with the phrase shoot the breeze, both the literal meaning (shooting a gun into the air) and the idiom (talking with your friends). Please don’t shoot guns into the air; what comes up must come down.
Watch here for a detailed explanation of how spray bottle work: