Knuckling one off

When an fat dumpy lesbian beats herself off and since she's so fat she aggressively rubs her knuckles on her puss to get off

Patti couldn't get the job done with her dildo so she ended up knuckling one off on that big fat pussy

Knuckle one off

The same as Jerking off or the 5 Knuckle Shuffle

Did you hear Nic Pledged a Fraternity?

Yaa now he sleeps and showers with 50 guys in the same room. He said he has to go into the bathroom to Knuckle one off!