A girl closely related to or one and the same as a "Cum Guzzling Gutter Slut" So ready for sex that she has a mattress strapped to her back at all times.
Rob's nickname for his girlfriend was either "Mattress Back Whore" or "Cum Guzzling Gutter Slut" though he rarely called her those names in public.
1. (noun) A girl who has sex so often, whether with the same partner (nympho), or many different ones(slut), that her back seems to be constantly on a mattress.
2. a condition derived by a girl who engages in said activities.
1. "That girl is a mattress back if I ever saw one."
2. "You're gonna get mattress back if you keep sleeping around like that."
a way to spice up any sentence in a way that even "your mom", "that's what she said", or "in your granny's oven" can not achieve; from the hit movie edward scissorhands.
Bob: I did some gardening today.
Fred: ...WITH A MATTRESS IN THE BACK!