Hmmm.. Jess. My son is 17, and he's still doing it and laughing. When he was 2 years old, he ran around for a year saying "Caca, bootie, farted" and laughed. My mother really wanted to break him of that habit as she took him to the Kingdom Hall once a week. Hehheh.
I was raised with four boys, and I still think it's funny. <shrugs> Must be the tomboy in me! My favorites were when my little brother, who could do it on command, would let em roar during the prayer at the meetings. He invariably had the whole row in front of us cracking up.
Oh well, I do realize that it's impolite, but boys all do that nonsense. I just can't think of a way to stop them.
CG