Little Drummer Boy

My kids sing the Little Drummer Boy refrain as "rubbing my bum."
Which I think it kind of funny though I feel hypocritical about that since I always tell them to stop when they start in on "Jingle Bells Santa smells."
I guess it's because they made up the "rubbing my bum" refrain themselves.
I can appreciate inappropriate lyrics only if they are original.

song: Little Drummer Boy • artist: Katherine Kennicott Davis