Not So Yummy Yummy

Here is an excerpt from last night's dinner conversation:
Me: So, Alex, what did you do at school today?
Alex: We made fruit salad!
Me: That sounds like fun.
Alex: (excited) Then I started singing the fruit salad song (begins singing Fruit Salad by the Wiggles.)
Alex: Oooh! (giggling) Then one kid started singing "Poop salad.. yummy yummy!"
Me: Really? Which kid did that?
Alex: (pauses) It was me.
Me: Of course it was.

I no longer wonder why his teacher gives me funny looks when I drop him off for school.