A new lick of paint
When a guy is getting a hand job and he cums so hard he shoots his load right at the wall like a damn spray can. The wall gets a shiny new mark that looks like it was painted by a messy kid.
He came so fast he hit the wall like a bullet.
The wall got a new stain because he couldn't hold it in.
He sprayed the wall with his cum like it was a graffiti session.