pot, potty, poop

Me: See, p.o.t. spells pot, like a flower pot.
Jake: p.o.t... like potty? Can you spell potty?
Me: *sigh* p.o.t.t.y.
Jake: p, p, p, poop! Can you show me how to spell poop?
With a 4 year-old boy, even a spelling lesson with flowers results in an excited drawing of poop.