monkey sheets

Bed sheets stained with spooge because you masturbated and then subsequently ejaculated onto them.
Monkey sheets are frequently characterised by having a queer odour.

{Beavis and Butt-Head dressing themselves as ghosts for Halloween}

{Beavis}: Hey Butt-Head, this sheet smells funny.
{Butt-Head}: Yeah, huh huh. Those are my special monkey sheets.
{Beavis}: O fuck! Get it off! Get it off!! GET IT OFF!!!