When you ejaculate into your hand and slap somebody else with the hand you ejaculated into across the face.
"If you dont stfu im going to J-Slap you."
"Dude Amanda didnt shut the fuck up last night so i had to J-Slap her."
"Dude Amanda didnt shut the fuck up last night so i had to J-Slap her."
by CowNiggaBalls November 26, 2011
A j-slap is when a romantic partner licks his or her hand and slaps a girls vajayjay (vagina) to lubricate and excite their partner.
by kathom86 April 05, 2013