My new spouse is much younger than me. Since my wife's mother is a widow, we ended up living together. My mother-in-law has big breasts and a plump body, her face is adorable, and she's close to my age, so we get along well—she's exactly my type. Then one afternoon, I accidentally saw my mother-in-law masturbating and couldn't control my reason. I said to her, "If you're feeling unsatisfied, I'll satisfy you," embraced her, and ended up sleeping with her.