Why we don't say POOPIE at the table.

(At a meal time)
Léo: " Mom? I need to go POOPIEEE!"
Mom: " Okay, go. Next time, just say you need to go to the bathroom instead."
Léo: "Okay."

(Léo returns to the table)
Léo: " Oh. I know WHY you said I should just say I need to go to the bathroom instead of POOPIEEE. "
Mom: ?
Léo: " Because you never know what comes out until it actually happens!!! "
Mom: ?!