I remember my hands trembling with excitement, gently stroking your panties.

They were clean, cotton panties -- straight from the bureau, white, with a tiny satin bow on the front of the waist band. They weren't sexy panties, sheer or lacy, just every day panties. I didn't need anything more.

I was utterly entranced as my fingers delicately touched the fabric, my mind racing, knowing this had clung to your most intimate parts. I couldn't help but sniff them, but couldn't smell anything other than the faint sweet smell of Tide detergent.

I jerked off right there in the middle of your room, my pants dropped around my ankles, coming quickly, moaning as I shot my load into the crotch. A few moments later, sweaty and a little terrified of what I'd done, I buried the panties in the middle of your laundry basket.

I was 18 at the time, about to leave for university. You were 14, my half sister, a late bloomer who had transformed into the subject of my forbidden fantasies that summer.

I never told you about this, of course. Nothing ever came of it. I chalked it up to being hormonal teenager with a raging libido for anything female; the proximity of siblings, the harmless flirting and relaxed boundaries. I've worked through a lot of excuses, but the fact remains -- it's one of my go to fantasies when I'm horned out, and when I smell Tide detergent ... well, I'm in trouble.

But, we're older now -- you're well on your way to becoming a doctor, and I have a solid career and a young family. We keep up over email and chat, we share funny links with each other here on Reddit, and we're in a good place.

I'm proud of my little sister. You're amazing!

Now you're back in town for several weeks, studying on exchange at a local university. You're staying at our dad's house, in that same room. Last weekend we had the whole family together, drinking wine into the wee hours of the morning. You, my wife, and myself -- the middle generation -- had a good laugh about kids and sex and the Internet and people's weird kinks.

You mentioned this subreddit. It was an off hand remark. You and my wife were joking about racy writing, I think. You recommended she come here to play with desperate young men I was out of town on business. We all had a good laugh ... but you gave me a fleeting look that made my heart leap.

I know you're here. I'm hoping you read this. I'm hoping you send me a note, confessing your lust -- even if it was just for a moment when we were young.

I dare not hope for more ...

Your loving brother,

Chris.