The most erotic thing I have ever done... so far.
I have a sister who is 20 and she stayed with us for a week. We are both really into fitness and running in particular. So, last Sunday, we went out for a run. 12 miles of really quite lively pace. When we came back we were both hot and sweaty. My husband Chris, had treated himself to a lie in and was sitting on the bed when I came into our room to strip before hitting the shower. He grabbed me as usual and told me how he loves my sweaty scent after a run. I could feel his hard on and was quite flattered.
I rubbed him a little and told him how wet I was and then said 'If you think I'm wet and sweaty, Alison was sweating way more than me. Imagine how SHE must smell.' I felt his hard on twitch into something truly massive, and right there and then in that moment, I had the most erotic thought. I kissed hubby on the cheek and ran out of our room and up to Alison. I breathlessly told her what I had said to him and came straight out with 'Can I take your panties down to him?' She said I could but that there would be a price that she would tell me about later.
I grabbed her wet panties and ran back to my husband. There, in the bedroom, I held my sisters panties to his face while I jacked him off. All the time I kept talking to him about them. 'Just imagine, Alison's smooth pussy lips against the material. See how sweaty she is? I wonder if she peed a little as we ran.' Suddenly he blew the most massive load right across the room. He said he came so much it actually hurt him!
Later that afternoon, Alison told us of her price. It was for my husband to bring her off while I watched. Well, it started off like that but soon I wanted to see him do more than that so I can't tell you about what happened next.
That night, we made love. It was the most erotic night of my life... so far!