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1.
The same thing as a sixty-nine (69), but with both parties pissing.
Person 1: Dude, I heard that Brock and Misty were pissty-nining over the weekend.

Person 2: Why do people pissty-nine? Its nasty.

Person 1: Don't knock it till you try it, bro.
by Mr.Monopoly? December 30, 2011