I work for a company and live alone in this house. My wife, who is the main earner, is often away on business trips, and when she comes home on the weekends, she is often asked to give me sex as if to relieve stress, which leaves me exhausted. Perhaps out of concern for me, my sister-in-law Nao often comes to visit us. I complained to Nao about the 30 days of abstinence she has been forced to abstain from sex in order to have a baby, but Nao touched my crotch with an awkward smile and whispered that if I could endure it, I could do whatever I wanted with her...