A Strawberry Shortcake is when a woman is on her period and rides a mans face until climax. Thus making a "Strawberry Shortcake"
Man: Sit on this face bitch.
Woman: I can't I'm on the rag!
Man: It's ok, I've been craving some Strawberry Shortcake anyway!
A Slut Muppet is an individual who is easily controlled by/in sexual situations.
One who will do just about anything to get laid and/or can be bribed with very trivial items to gain sex from them.
Guy 1: Dude your sister is SO hot! But I think she's out of my league.
Guy 2: You're right, she's too hot for you, but have no fears, cuz she's a Slut Muppet anyway!