this is a very old one, but still one of my favourites.

this fellow goes out at the last moment to buy the xmas present for his wife and finds that most of the shops are closed.
he rushes around all over town, and eventualy finds a pet shop, the owner just about to shut up shop.
he explains his dilemma, and the owner sez all he has left is a cock-sucking toad.
sceptical, he asks for a test-drive, and finds the toad does the most amazing bj, so he buys the thing and sets off for home.
on returning home, he finds the wife frying chips, sets the box with the toad in it down on the table, and sez:
"merry xmas, dear, i got you a present"
she opens the box and asks him what the hell he was thinking.
he explains that it is a cock-sucking toad, and the thing really does do an amazing bj!
"what the hell am i supposed to do with it?" asks the furious wife.

husband's reply:
"TEACH IT TO FRY CHIPS AND FUCK OFF OUTTA MY LIFE!"