One evening after returning to my parents' home, I found my sister-in-law cleaning my room wearing a short skirt. She had on pantyhose, and I could see her panties underneath, which instantly turned me on. Unable to resist, I started secretly jerking off, terrified of getting caught. But to my surprise, my sister-in-law didn't scold me—instead, she became deeply curious about my cock. It turned out she'd been suffering from a sexless marriage with my older brother and was struggling with intense sexual frustration. Before long, an unspoken bond formed between us, and we began secretly touching each other, avoiding the family's eyes. We escalated to oral sex, and eventually, unable to hold back any longer, we had full intercourse when everyone was away. We fucked hard with relentless thrusts in places that excited her sense of shame—the hallway, the kitchen—until both our desires exploded.