I had s*x with my mother-in-law on her silver wedding anniversary. It was amazing and she's made it clear she wants to do it again. I'm 26 and. My husband had sex with my mother (his mother in law 3 years back). I was pregnant for the 2nd time and my husband was horny as hell. The affair was discovered by the year-old woman's son on March 17, , “My mother-in-law had sex with me out of her own free will in.