Two women are getting ready for bed on Christmas Eve. One goes to say goodnight to her housemate, and sees her in her room sleeping above the covers, spreadeagled and naked with a plate of cookies and a glass of milk at her crotch.
When the first girl asks "What are you doing?", the naked girl says "I don't know if it's a dream or not, but Santa always comes, eats the cookies and milk and then we have some wonderful hot sex."
The other girl says "I'm really horny, I'm going to try it too."
Next morning, the first girl is in the kitchen all aglow, whistling and making breakfast. When the second girl comes down, she looks like death warmed over.
The first girl says, "It happened again - Santa came, ate the cookies and milk, and we made glorious love. Look, he left me a note; 'Merry Christmas Tracey, thank you for being a naughty but nice girl again. See you next Christmas, Santa'."
The other girl says "I feel like shit, look at my note: 'Thanks, you were great - from Rudolph, Dasher, Prancer, Vixen...'"
Best to leave bestiality out. Pun intended