A sexual act performed by a male/female couple and a third which can be male or female. The couple prepare for sex in the doggie styleposition. The third party then cups the male's balls in the palm of their hand and extends their middle finger out and along and against the bottom of the male's cock. The male then proceeds to enter the vagina filling her with both his cock and finger of their partner at the same time. Thus giving her a satisfying knob and knuckle.
Joey and Sasha had a threeway with their firend Lou. She was most satisfied when Lou and Joey gave her a Knob and Knuckle.
by Tugg N. Harder July 03, 2009