Back in the early 90's a lot of girls used to wear really tight old cut off jeans, usually guy's jeans that they had recycled. My sister had taken an old pair of mine and turned them into daisy dukes, I couldn't help but notice how great they showed off her ass.
One day as my sister was getting into the shower I noticed the cut offs on the floor in her room, my parent's were gone to work and my sister likes to take long showers. It appeared my sister did not wear any panties with the shorts, I picked them up and sniffed the crotch, they were damp with her pussy juice.
I took the shorts back to my room, pulled out my throbbing cock and jerked it as I sniffed the cut offs. I thought about my sister getting horny while wearing them without panties. I was going to cum, so I laid them on my bed with the back pockets facing me and shot five globs of my spunk on the jeans. I quickly returned the shorts to my sister's room.
Later that day my sister came downstairs to watch TV with me, to my surprise she was wearing the cum stained cut offs. The sight of the dried cum on the back of her jeans made me hard as a rock. She laid on the floor on her stomach watching the tube, so I was able to rub another one out while I stared at her ass in those cut offs.