His Highness is smack in the middle of a big potty-talk phase. Pee-pee-this and poo-poo-that and so on. He has mostly moved past the completely made-up words, so this is progress in its own little way. As for my response, depending on the circumstance, I vacillate between ignoring it, replying with an immature phrase of my own ("YOU are!!" etc), and explaining when & where potty talk is appropriate, and that most people don't like it randomly inserted into conversation. Some do, but most don't.
So tonight I was lying down with the boys at bedtime, and we said a prayer to thank God for the day. I ended with an "A-MEN!"
The Littler One said "A-MEN!"
His Highness said "Pee-pee-amen!"
Nice touch, son. Nice touch...