The potty humor, that is. I guess boys never really grow up since John was the one who started it all...
John: "Wanna hear a secret?"
Ben: "Yeah."
John (whispering in Ben's ear): "Fart."
Ben: laughs
John: "Go tell mommy your secret."
Ben: "Mom, come fart in my ear!"
Mom: Gives dad the evil eye, but can't help laughing out loud.