Here we have a lovely little group by the name of The Little Stinkers, with "I Farted on Santa's Lap (Now Christmas is Gonna Stink For Me)". I really just stumbled upon it and loved it immediately, and think you will, too. It makes me think of the children's book "Everyone Poops", in the last stanza of the song, anyway.
I got it from the blog Musical Knowledge, and linked to the song directly (naughty!). In case the direct link fails.
So yeah - check it!