What does the term 'donkey punch' refer to?

Question

My brother wont tell me and yes, i'm old enough to know.

Answer 1

go on this

http://en.wikipedia.org/wiki/Donkey_punc...

for a full explanation.

Answer 2

It is when you are having '5exy time' with a lady from behind and just as you are about to 'spill your seed' you punch her in the back of the head to see how much she tries to kick you off... rofl