This sibling role-play is performed by adults. “Big brother, I only want to have sex with you.” Nana, my once-clingy adult sister, suddenly gazes up at me with round eyes and sweetly takes control. She happily licks my nipples, sucks my cock with a blissful expression, then straddles me and rides on top. Even after I ejaculate, she keeps asking for more—and I fall for her harder than ever.