Licking of the anus.
It's like licking a 9 volt battery, you know you shouldn't do it but you do it anyway...
You 9 volt your girlfriend.
You lick the ring hole - 9 volting.
As a payout: gary 9 volts joe - he is a 9 volter.
licking of the anus
the feeling you receive when licking a 9 volt battery is the same the kinda tingling feeling you get when licking the anus, hence the term '9 volting'.