The wife gave birth, the husband sent his wife to his parents' house to take care of and the ending was that he had an extra pair of horns on his head that a... another child. Taku is a second-year college student. He stays at his parents' house and lives a freelance student life. But his carefree life gradually ended when his stepsister who had been married for a long time suddenly returned. Because of the birth of his second child, his sister went to his parents' house to easily raise the child, while his brother-in-law still stayed at his old house to facilitate his work. When he was at home, his stepsister always let loose her big, round breasts full of breast milk in front of him, and underneath she wore nothing but T-back panties, which made her entire body almost completely visible in front of his eyes! During a drink together, she deliberately teased him by provoking him to suck on her milk. But unexpectedly, Taku agreed, unable to retract his words, his sister had to let him suckle milk. Taku repeatedly stimulated the nipple with his hand before sucking, causing his sister's milk to spill out. In retaliation for Taku, his sister also "sucks" his milk, and Taku also quickly surrenders to the charm of his stepsister and produces "milk". But how could he end this here? He pressed his stepsister out to fuck, although she kept resisting, she always followed him, blending in with his clicks. And the wrong relationship of the two began from there. After a while, his stepsister got pregnant, because she also had sex with her brother-in-law during this time, so he didn't need to worry, and he could still continue this wrong relationship with her...