Rats in my ass

The phrase “rats in my ass” can be used a few different ways such as, “damn” or “dang I thought I almost tricked you”
The phrase can also be used as a verb after you do something wrong.

Addie: “Hey what’s your address?”
Jordan: “gives address”
* a week later*
Jordan:“hey Addie what gift are you sending me?”
Addie: “what are you talking about?”
Jordan: “rats in my ass”
*a week later a gift arrives*

Rats up my ass

Punching your hand inside someone's asshole and then you open the asshole and tickle the inside.

The sensation feels like rats crawling up your ass, hence the name.

Nick (you, a kinky motherfucker): "Man, Lisa just gave me rats up my ass."
Mike (your childhood friend who respects you very much, up until this information which has entered the neurons in his brain matter): "What the fuck?"

Dead Rat in my ass

What Red Dead Redemption should've been.

Tyson: Hey, did you get Dead Rat In My Ass yet?
Samuel: Nope, I do have "3 Snakes in My Colon 2" however.