It all started pretty innocently... at least I thought so at the time. I'd been going to The Body Center for a few months. It's a pretty nice - but not too expensive - athletic facility near where I work, with weights, an indoor track, basketball and racketball courts, a pool, and so on. Not only is it affordable and convenient, there are a lot of hot guys who work out there. So I'd been spending quite a bit of time there, and I was getting some pretty nice results. At least with my physique... I was too shy to try hitting on any of the other guys.

One weekday, I'd just finished a fairly relaxed half-hour workout during my lunch break. I stripped out of my sweaty gym shorts, jock, and shirt, and I headed for the showers. The Body Center's a pretty safe place, so I left my locker unlocked. I spent about 10 minutes in the shower, long enough to clean off and cool off, and just long enough to scope out the other guys without arousing suspicions that I was... scoping out the other guys.

I went back to my locker, dried off, and started to get dressed. Except my underwear was missing. I checked under the bench, looked around on the floor, even checked the empty lockers on either side of mine. Nowhere to be found. All I could figure was that some kid had swiped them as a practical joke. But I didn't see anyone watching me and snickering. The jock I'd worn for my workout was wet with sweat, but it seemed better than going "commando", so I put it back on and put on my work clothes over it.

The jock felt weird under my khakis, and I spent the rest of the day semi-hard thinking about it. Every time I glanced down at my crotch I saw my basket sticking forward in that musty but supportive pouch, which just turned me on even more. By the end of the day, I was so horny I had to jack off as soon as I got home.

I went back to the Body Center the next day, and brought an extra pair of underwear along, just in case. So imagine my surprise when I got back to my locker after my shower and found three pairs of briefs in it! I sniffed one pair, and it was the clean ones I'd brought along as a spare. The next one had the familiar crotch scent: the ones I'd worn that morning. The third pair smelled similar... but a little different. It was as if someone else had been wearing them. And it smelled good!

On impulse, I put them on. I had to finish dressing quickly, because I immediately had a boner and I didn't want anyone noticing it. I was rock hard when I got back to work, and had to jack off right there in the parking lot to release the excitement, using my briefs from that morning to catch the cum.

The next day, I wore those briefs to work, the ones I'd jacked off into. They were dry, but I could smell a hint of what they'd been soaked with the day before. At lunch I went through my usual work-out, then headed for the lockers. I left the cum-stained briefs in my locker, the door ajar. I had to shower facing the wall the whole time, because I was sporting a stiffy that would certainly draw attention.

When I got back from my shower, I was disappointed to see that the briefs were right where I'd left them. But as I pulled them on, I suddenly felt something warm and oozy spread across my cock and balls. It was fresh cum. Still wet, and still hot.

I glanced around the locker room to see who might have done it. There was no one in a direct line of sight from my locker, so whoever did it wouldn't have been seen. Just around the corner there was a cute teenager - 16 or 17, I guess - slipping into his baggy jeans. My cock began to slither through the man juices in my undies. He glanced at me, but didn't pay me any attention. Looking the other way, there was a guy in his mid-30's with thighs to die for and beautiful blue eyes, but when our eyes made contact, he didn't react. My cock was straining against the damp fabric, as I grabbed my towel to hide it. Two college-age weight-lifters with absolutely stunning arms and chests showing under their t-shirts walked out together chatting casually. It could have been any of them. Or someone who'd already left.

I couldn't go back to work with a fresh load of jizz in my underwear, so I went back to my locker to change. I'd tucked another pair of clean briefs into my pants pocket... but they were gone! So was my damp jock. The guy had taken all my spares! I was going to have to spend the rest of the day with nothing at all between me and my Dickies. I quickly got dressed, found a bathroom stall, and relieved my aching hard-on into my still-oozing briefs, adding my own hot juices to... his. Even so, my dick kept springing to life every time I thought about it for the rest of the day. I jacked off into the briefs again when I got home.

The next day was Saturday, so I didn't have to worry about my underwear adventures intefering with my job... or vice versa. I wore the jizzed briefs - which were dry again, but getting a little crusty - to The Body Center. As I walked into the locker room, I was rock hard. I couldn't work out like that, so I put down my duffle bag by my locker, went into the bathroom stall, removed the briefs and jacked off into them.

I quickly stashed the dirty briefs in my locker and proceeded to get undressed to put on my work-out clothes. But my jock was already missing! I looked around, and didn't see any of my suspects from before, just a trio of high school boys, a middle-aged man and his 10-year-old boy, and a couple of guys in their mid-20s. None seemed to notice me, as I put on my gym shorts with nothing underneath. I locked my locker.

I put in a quick workout, but my mind kept racing back to the locker room, and so did I. When I got there, my jock was hanging from the padlock! Sure enough, it was wet with jizz. Frantic that someone would notice, I quickly opened the locker and stuffed it inside. I tossed my sweaty shorts and t-shirt into the locker with it, and headed to the showers. The three high-schoolers I'd seen earlier were in the shower with me, and as I rinsed off I noticed that they were stealing glances at me, whispering to each other, and snickering. Aha! I thought. They're the ones! Then I realized that I was sporting a hard-on, which was probably the source of their amusement.

I quickly retreated to the locker room, where I saw that in my haste I'd left my locker open. Nothing was missing, but someone had taken the cum-filled jock and briefs and smeared the goo - mine and his together - all over the inside of my jeans. Baffled, I put them on and went home.