QOS♠Wife2~Shikyuu ga Kuroi Kyokon ni Seifuku sare Daraku shita Kyouki na Hitozuma~

This is the story of a feisty newlywed wife who meets a black man and gradually descends into depravity.
Because the protagonist lacks sexual prowess, he helps his wife find a suitable man. When she meets a tall, muscular black man, she begins to act strangely… She’s found with oversized condoms in her bag, wears revealing outfits she’s never worn before, and has mysterious black tattoos on her body…

[Edited from DLSite]