While my wife was away, my wife's younger sister confessed her feelings and I had sex with her. (Iga Mako ADN-374)

"I've liked you since the first time we met. But you married my sister... I still can't let go." My sister-in-law's confession made me very happy. My wife wasn't home; it was just the two of us. No one bothered us. "If only my wife didn't come back..." I was so obsessed with this relationship that I even had such dangerous delusions.