I missed this response to the "Who is the real father" joke ... There is an old tradition to have a pool where everyone tosses in, say, $20 into a pot with a guess as to whom the REAL father is. Guesses like "Mick Jagger" or "Wilt Chamberlain" are tossed about.
If you guess right, you win all the money, if NOONE guesses right, the money goes to the new parents. Of course, noone EVER guesses the real DAD. Come to think of it, that would take the fun out of it ...
It is a way to have fun while getting to the new parents a few hundred needed $$$$.