Panty Fap
When an individual with a panty fetish incorporates panties into their masturbatory rituals. This may include, but is not limited to, wearing panties, sniffing panties, shoving panties into a bodily orifice or holding panties in their fapping hand and physically wanking with them.
I stole some of Rachel’s undies last night out of her gym bag. I’ll be doing a panty fap tonight.

He wrapped the pair of lacy panties around his engorged knob and busted one out from a panty fap.