Living with my older brother and his wife, I’ve constantly been exposed to Karen, my sister-in-law, either putting on passionate sex shows with my brother or deliberately revealing her naked body while bathing. Unable to resist her relentless seduction, my desire for her grew stronger each day. Finally giving in to temptation, I started masturbating while sniffing her used underwear—only for her to suddenly walk into my room and ask, “What were you imagining just now?” The atmosphere shifted instantly, plunging me into an even more intense and thrilling situation.