knuckles over 

Instead of masturbating in the traditional way, you place your hand on your cock, palm down which in turn is knuckles over....

He was so sick of pulling himself the same way everyday, he decided to go knuckles over for a change..

knuckles over by Sodamiza69 May 11, 2016

Throwing one over the knuckles 

When a male is masturbating and the jizz runs down over his knuckles after he has blown his load.

Mike needed half a box of Kleenex after throwing one over the knuckles.

Throwing one over the knuckles by Meromero May 5, 2017