When you spank someone so hard they immediately ejaculate all over the ceiling or floor (depending on which way they’re bent over).
Example 1: I spent all day cleaning my ceiling after I hanky spanked Vanessa and Leroy last night. It straight up smelled like salty fish and swamp water.
Example 2: Kimberly enjoyed being hanky spanned so much, their ceiling starting growing black mold from the excessive moisture.
Example 3: “Dude how did you break your wrist?”
“I hanky spanked Kyle on the kitchen floor last night and slipped on his cum making a sandwich at 2am.”