Fuckstain

A word that is used to describe a person, usually an ex lover or fuck-buddy, as worthless. One that has little or no value to you.

Can also be used as a way to say that person is/was a waste of time.

“ You were nothing but a fuckstain.“ (Jamie’s to Mike 51)
“Who? Oh, that fuckstain, Mike, oh yeah, what a loser!” Lol