The sister who uses her brother's penis to relieve stress and sweat. The sister is a sporty girl with an insatiable sexual appetite and a well-trained body, with the added bonus of being a pervert who rides her brother's face and sniffs out the taste and smell. She performs deep throat on her own or asks her brother to cum in her mouth, getting saliva all over. Their sexual desires never end, and in the end, they engage in thick, impregnating sex while strangling each other, a story of a twisted sexual perversion of a sadistic sister and a masochistic brother.