*doesn't know to quit when ahead*

This is how the relatively painless donkey punch is supposed to work, according to my friend:

When you know you're about to blow your load, rather than punch your partner in the back of the head, you simply deliver a not-so-forceful chop to the base of their neck. It (apparently) produces the same results.

This will self-destruct in...erm...a while.

*poof!again*