Potty Humor

Bennett is really into potty humor. We've had to ban the words "Fart" and "Poop" and new words are being banned daily. The other night I was laying in bed with him and trying to teach him his birthday, so I would say "Bennett your birthday is November 2" then I'd ask him "When's your birthday?" and he'd say something silly like "November bed" or "November Book" naming different objects in his room rather than the date. I kept trying until he answered with "November Pee". I said "Bennett that's a potty word we don't say that" and he answered by saying "I said Pee like the letter". One word Manipulative!
Another time I was on the phone with Sarah and we were on speaker phone when she told one of her kids "We don't like potty words" Bennett perked up from his playing and said proudly "I like potty words, POOP". What am I going to do with this kid?