The cupcake mystery

I found some cupcake leftovers smudged on the floor(carpet), so I reacted.

Me: Oh no, who left this cupcake here?

Ethan: Daddy, who do you think did that, is it Ethan or is it Mama? I'll give you a clue, HE is strong... and fat! 

Me: Then it's you! Who else can it be? 

Ethan: Daddy, that's still a mystery.