Poo pee

Parent: want to go tee tee?
Child: No!
parent: want to go poo pee?
child: No!
parent: want to go pookah? ( or whatever you word is for flatulence)
The child always erupts in laughter. Worked great for my 3.5 YO. She thought and then laughed at the joke about 10 times in a row until I decided to stop and make her and her sister ( who also laughed heartily ) leave the play palace with me at Burger King. My guess is that she evaluated solids, liquids, and gases, knowing that making gas did not require a trip to the potty.