Boys-One in Particular

So I sent Joel out to the mailbox for me. He returns in tears.
"Mom, John just shot me with the airsoft gun."
"Huh?" was my response.
I go outside to find the culprit because I really can't believe that his brother would just hide behind a patio wall and shoot his younger brother who is on his way to the mailbox on an errand for his mother.
I yell, "John!" "Did you shoot Joel with the airsoft gun?"
"Yes!" he replies.
"Why would you shoot your brother with the airsoft gun?" I ask
His explanation? "Because I wanted to."