I live with my wife, my mother-in-law, and myself. Although my mother-in-law hasn't directly said it, the atmosphere conveys that she wants to see her grandchild. However, even though I want to show her the grandchild, my wife won't cooperate, and I've been living in frustration. Today, I witnessed my wife and mother-in-law cleaning side by side, and I got excited by the two moving butts. At night, when I tried to have sex with my wife, she said she wasn't in the mood, so I pouted and left the bedroom. Trying to calm down and sleep, I noticed a light coming from my mother-in-law's room. Usually, she would be asleep by this time, so I approached and heard faint breaths. Peeking secretly, I saw my mother-in-law in the middle of masturbation. Her experienced, sticky fingers played with her private parts, and her cheeks were pink. I couldn't resist and went into my mother-in-law's room. When I hugged her, I traced my fingers over her crotch. Her already wet private parts gently accepted my fingers. My mother-in-law resisted, but when I confessed that I couldn't hold back because I hadn't had sex with my wife, she said she forgave me and satisfied my raging cock with her hands and mouth. The next day, I skipped work and, after confirming my wife had gone out, quietly locked the front door...