I found used panties
I have always had a panty fetish. I began wearing my sister's panties at an earlier age. I don't know why I loved them, but I would take a pair of her cotton flowered panties to the basement and wet (pee on) them. I would use a pair for a while until they were crusty, then get a new pair. Eventually I developed and began to come in them.
Many summers ago when I was around 13, our family rented a house on a lake in Wisconsin for a long weekend. On the last evening we were spending at the house, while my parents were out, my sister went looking for a deck of cards in the bedroom she was sleeping in. She opened up the night stand next to her bed and started yelling. In there she found a pair of dirty panties. These were not little girl panties like I had worn before, they were white silk bikinis with blood and yellow stains. I told her that they could belong to the owner, so that she should just put them back where she found them.
We finally found a deck of cards and began playing some game. Neither of us had changed out of our swimsuits from our earlier swim. She spread her legs in a 'v' as she sat on the floor and it didn't take me long to notice that she had light brown hair sticking out both sides of her suit bottom. I was amazed and couldn't stop staring. I hadn't expected this growth from her as she was still flat on top and I think she had more pubic hair than I did at this point. We played cards for about two hours, and no matter how she adjusted her legs, I was always able to see her pubes. I had such a hard on I laid down on my stomach for a while so that I could peek over the top of my cards and see her beautiful new bush. Eventually I sat up and I didn't care if she saw that I was hard. To this day I'm not sure if she was trying to show me anything or not.
After cards, she went to bed and I stayed up because I was so excited. I knew I had to jack off, and I remembered those soiled panties. I waited as long as I could hoping my sister was asleep, then I snuck into her room and took the mysterious panties. I went to the bathroom, put on the panties and came all over my stomach in about two minutes. It was only around 10 o'clock, and my parents were still out, so I returned the panties to their spot and went to watch some TV. About 20 minutes later I was still so horny, I went back to my sister's room and took the same panties back to the bathroom. I had never been past second base with a girl at this time, so this time took some time to study the panties. I sniffed the crotch until I couldn't take it anymore. This time I deposited my load on top of the other already present stains in this unknown person's panties. I folded them up with all my goo inside and put them back in the night stand next to my sister's bed once again.
I thought about taking the panties home with me the next day, but was afraid I would get caught with them. It was also exciting to think that maybe the owner of the panties would find them with my new addition. I still whack off thinking about those panties.
For the last 25 years or so I have continued to love panties, I buy them, borrow them, take them from others. As I type this I am wearing my wife's thong and bra, and dripping wet. She doesn't even know. More stories to follow if you like.