Rug smudger

A person who drags their bare ass across someone's carpet or rug leaving a skid mark (a line of fecal matter) on said carpet or rug intentionally.
Also used for someone who ejaculates into another person's pubic hair.

That rug smudger ruined your new carpet, you may never get that stain out.
Or
He pulled out and came on my pubic hair, what a rug smudger.