Dream come true
I had been using my sister's panties to masterbate for a couple of years now and it never failed to turn me on.
I was 15 and she was 20, she was about 5'2', had a great ass and great firm breasts, she wasn't skinny but by no means fat. She wore glasses a lot of the time and was a very hot looking girl.
Our bedrooms were beside each other so I could hear when she went to take a shower, she would always put her clothes into the wash basket outside the bathroom door. This was when I would sneak out and take her still warm and moist panties from the top of the pile, put them on, sometimes with her 36dd bra.
When she would go back to her room to dry off and dress I would look at her through her door as she couldn't shut it fully. I would put her panties on and I could feel the wet warm patch of them against the underside of my balls. As she rubbed moisturiser onto her body I would work myself up to orgasm.
This went on until one day when I was about 19 and she was 24. I had just returned to my room from watching her while wearing a pair of her blue satin matching panties and bra with a hand full of cum. I walked over to my desk to get some wipe's and as I turned I was greeted by my sister standing there in her robe. She had a blank shocked look on her face. She walked over to me not saying a word, put her finger in the waistband of her panties, which I was now wearing, and dropped them to the ground. She put her arms around me to take off her bra which I was also wearing. My cock was instantly hard which I'm sure she could feel against her lower belly or possibly her pussy. She picked up her panties and wiped the cum from my hand and then the tip of my cock.
She just smiled and walked out of my room. I've never been so embarrassed or turned on in my life. I didn't chance it the next day until I got a text message on my phone saying, OUTSIDE YOUR DOOR, PLEASE DON'T LET YESTERDAY GET IN THE WAY OF YOUR FUN, I WON'T, KISSSES XXX,. As I opened my door I found a pair of the sexiest panties I had ever seen, white silk which had a large wet patch on them, a lot more than normal. She must have masterbated in them just before she left them on my door handle. She had bought them just for me.
I continued to watch her for another few weeks and each day she would knock on my door, open it a tiny bit and leave a pair of just worn panties inside my door so mom wouldn't find her underwear hanging on my door. She would leave her door open more and take longer to dress every day until one day when nobody else was home she asked me in. That's a story for another day. Not too sure if I'm allowed to tell it here.