the female version of a "dick slap"; when a woman puts her pussy right in a man's face holding the right or left labia majora aka outer lip to then slap his face with it.
*this can also be done with both outer lips
"was that dessert?" he said.
"uh no, it was a vag slap... my version of a dick slap you sarcastic bastard," she responded as she pulled the front of her skirt down with a smile.
A vag slap is when a male or female decides not only to play with, in, or around the vagina hole but instead initiates a slight pat of the vag. A noise follows and your dignity falls. Usually two slaps occur in a synchronized fashion, such as *Slap Slap*. There is a corresponding song that goes to the beat of "Can I Get A Clap Clap?" but instead the lyrics are "Can I Get A Vag Slap?"
Arbys Employee: Welcome to Arbys, home of the fucking bombest food ever, what can I get you?