Farting the alphabet

Peanut: It's "F" week at school. For "F" week, I'm going to fart in a bag and bring it in.
Me: Nobody can see a fart.
Peanut: For "B" week, I pulled down my pants and showed everyone my butt.
Me: You're such a liar.
D: If you did that you would have gone straight to the principal's office.
Peanut: I didn't, but Stephen did. For "A" week, he showed everyone his anus. And his wiener.
Me: Clearly, Stephen doesn't know the alphabet.
Peanut: He did. For "B" week he showed his butt and he had to go to the office.
Moon: What did he do for "C" week?
Peanut: Oh, for "C" week he just put some candy in his anus.
Moon, laughing: Candy in his anus.
Peanut, laughing: And for "E" week, Stephen put an elephant in his anus.
Me, not wanting my son to mess up the alphabet: Wait, wait, wait. What happened to "D" week? Was Stephen absent for "D" week?
D: He was at the Dr. having things removed from his anus.