Trash walls

Basically, The inside of your asshole.

Girl: Shoot it in my trash walls!
Guy: What?
Girl: My ass...

Wall Trash

Those generic tattoos that you see on the wall behind those cheap plastic frames at a tattoo parlor. Most commonly found on college students, middle aged women, those "oh i just want a rose or a butterfly" type people, and anyone else following a tattoo fad.

"did you see that cross jose got tattooed on his chest?"
"yeah man, i saw that same cross on julio's arm!"
"i can't believe those two fools got the same wall trash tattooed on themselves."