A Grouch!

I am at the computer listening to the girls who are doing an art project:

S - Go to the bathroom Morgan (said with a little sass).
M - Why?
S - Because you are holding your crotch.
M - What is a grouch?
S - Not a grouch, a crot-ch. You have to go potty.
M - I don't have to go potty.
S - Yes you do.
M - No I don't.
S - Yes you do.
M - No I don't, I don't have to go potty (on and on).

Mom - Do you know what a crotch is Morgan?
M - A bagina? (Shrugging with a perplexed look)
Mom - Yes.