My brother in law is now a phone sex knicker lover!

Whilst staying at my Sisters house for the weekend recently I found out my Brother in Law is a dirty little knicker lover. I’d been out shopping with my Sister and I’d come home early, I opened the door and could hear noises from upstairs I shouted his name but he couldn’t hear me. I went up and saw his bedroom door open. I looked through the crack in the door to see what was going on and he was watching porn whilst wanking. I was shocked at first but kind of turned on at the same time, and felt a rush go through my whole body, as I continued to watch I could see he had a pair of my knickers in his hand and he was smelling them! I thought he was a dirty sod but couldn’t take my eyes of him, and started to play with my pussy, I felt as naughty as him because I was watching. I crept back to my room after I had seen him cum and I had a gorgeous orgasm whilst thinking about what I’d just seen. That night we’d all been out and my Sister was a little drunk and gone to bed, I told him what I’d seen and he was clearly embarrassed and asked me not to tell my Sister. I said I wouldn’t but I wanted to watch him again, and I made him make a phone call and have phone sex whilst I peeled off my sticky knickers and watched him doing it again describing to the girl on the phone what he was doing and why. I was in control of his knicker fetish and I loved it.