The act of masturbating over ones partner, and upon ejacualation, the ejacuator let's go of their penis, allowing the head of the penis to smack the Taint of their partner below. Usually in an upward or lower swing. Must be done with an erect penis, to allow proper "tension" swing.
by Lol_you_people_ June 25, 2018
Get the Masterbaint mug.