I forgot the manga's name but its about a couple relationship torn because of blackmail, the girl idolizes this singer who happens to be her boyfriend's friend and introduces him to her, but the singer is actually inlove with his friend, the boyfriend, so he blackmails the girl by allowing his band to gang rape her and took pictures of her being raped. He uses those pictures to get her to have sex with him because he wants to know how it feels to have sex with the girlfriend of the guy he was inlove with

Cross and Crime. I find the story quite intriguing and am waiting for releases