potty words

This is a conversation that took place this afternoon between Jonathan and Elijah:

• E: I know a lot of potty words Dad.
• 
  
• J: Oh, yeah? What are they?
• 
  
• E: There's the one that's poop, there's one that's pee pee, there's one that's toot and there's bathroom sink.

I just need to know who has been talking about bathroom sinks around my child. You think you've done a good job sheltering them from certain language and then they start talking about the sinks.