My friend and co-worker had just begun a training program with a few other women from work to prepare for a run that would be happening in a couple of months. Because I had previously been a semi-serious runner and had completed several marathons, she asked if I could possibly do some running with her to help her train.
I eagerly accepted her inquiry to me, relishing the opportunity to simply spend some extended time with her, although I greatly respected the fact that she was a married woman.
It didn't really occur to me that I would have the added bonus of regularly getting to see her in shorts, sweating, etc. until I met up with her that first morning. After arriving at her house, we first did a few minutes of stretching. I was pleasantly surprised when I immediately got my first quick look up her nice legs and even a little higher. Some different positions and angles allowed me to occasionally see all the way up to her panties and directly down her top (although she had on a sports bra). My heart began beating noticeably faster with each peek. My penis hardened immediately and I had to contort my body awkwardly to conceal the tent in the front of my pants from her.
Once we started running, my erection subsided, but when we finished and started cooling down a bit, seeing her sweat soaked top cling to her tiny breasts, the hint of hardened nipples showing through, and an improbable glimpse high up her shorts all the way to her panty crotch, made me rock hard in seconds. I did all I could to disguise my erection pushing straight out the front of my running shorts, but inevitably I saw her glance several times at my bulge. I was always careful not to have her catch me looking at her and making her realize I knew she was aware of my condition.
Once I returned home, I naturally had an intense masturbation session. Recalling all the looks of her thin, athletic body plus the fact that she looked at my erection several times made me shoot in no time flat.
It has become a regular routine now. Short run with her, masturbate at home immediately afterwards, masturbate later recalling all the details. I'm working on positions I can get into to allow her clear views under my pants and hopefully a clear view of my hard penis unobstructed through the shorts opening as I squat in front of her. My imagination is also making me envision her masturbating after I leave. Playing with herself in the shower as she thinks about my erection, trying to imagine what my rock hard penis looks like not covered up by my running shorts. Knowing how aroused I get by seeing her body (although she constantly comments about how small her chest is), she contemplates how bending in certain ways would affect how hard my penis gets. I also imagine that one day she throws all inhibitions aside and decides to run without a bra. She excitedly awaits seeing the tent in my pants grow as she realizes that although her breasts are small, her hardened nipples show clearly through her top and cause me to look incredibly uncomfortable as I fight myself from cumming right then and there in front of her.
Future goals include somehow getting a hold of her panties after a run, seeing up her shorts clear up to her crotch and possibly even a peek of some black pubic hair peeking out (a guy can dream can't he?), catching a hardened nipple poking at the front of her top, having to massage a cramp she may get, anywhere on her legs, but preferably high up her thigh, and the list goes on. Running is a great form of exercise for me and, perhaps more importantly, a great source feeding my masturbation fantasies. I never would have imagined running and masturbation being linked in any way, but as you can see, at least for me, they form an awesome combination that hopefully will continue and get even better.