Gosh, I know this was ages ago, but for anyone who ends up in a similar situation: As far as the the PDQ Bach (aka Prof. Peter Schickele) carold go, I heartily agree. They're hilarious w/out being offensive. However, Good King Kong might be a bit tricky if your relatives are a little rhythmically challenged. Another fine song is the 12 Days After Christmas, in which the singer & their true love have a fight & the singer does some spiteful things with the gifts. I don't know who this is by, though. Finally, if you can find the words to it, there's a song called "I am Santa Claus" (I think) to the tune of Ozzy Osbourne's/Black Sabbath's "Iron Man." I believe it's one of Bob Rivers' many twisted Christmas songs. I apologize if I've duplicated anything that's already been mentioned.