Anal Peek 

To stretch a woman's ass cheecks and peer into her anus, making sure she has not been having anal sex with other men.

"I'm pretty sure my wife has been assfucking other douchefags so I gave her a quick anal peek."

Anal Peek by Dan & Zach February 7, 2009

Anal peekaboo 

Hiding stuff in your anal cavity then making in go in and out without the use of your hands like peekaboo

That bitch be playing anal peekaboo with her dildo

Anal peekaboo by Jadedawg October 14, 2015