It was a crazy idea but he had no other choice when he had sought treatment in many places but still could not have children. It had been 5 years since they got married but Tsubasa could not have children because her husband had physiological problems, she had not even had an orgasm once. That was a real loss and misfortune for the slutty wife who was always craving for sex. The impotent husband had to ask his younger brother, a big and strong guy who was good at fucking, to help his wife conceive. Tsubasa felt resentful towards her husband, not because he was committing incest but because he did not bring his brother-in-law to see her sooner.