Last night, the person I hugged wasn't my wife; it might have been her sister... (Inaba Ryuka NKKD-147)

I've been married to my wife for five years, and her younger sister, Liuhua, often comes to visit. A few nights ago, I drank too much at a company party and, emboldened by alcohol, went to my wife's room and had sex with her… The next morning, hungover, I woke up to find my wife and her sister preparing breakfast in the kitchen. It seems I might have slept with her sister instead of my wife last night…