My third year in college I was living in an apartment with 5 other guys (3 bedrooms, 2 guys to a room) and the girls across the hall had bought a Playgirl magazine and torn out a page with a pic of a naked guy for some trick they were playing on one of the other girls, who later threw the page in the dumpster outside our building. I retrieved the picture from the dumpster and put it in one of my dresser drawers to use for JO material. (This was the mid 80s at a conservative Christian college in a small Iowa town, so no internet or easy ways for a closeted gay boy like me to get jack off material. I was lucky to get an International Male catalog, so a single picture of a naked guy was the motherlode to me.) Anyway, I placed the picture under some clothes in the drawer to hide it, but one time I came back to the room and opened the drawer and the picture was on top of the stuff, so I knew my roommate had found it. I didn't panic since I always thought he might be gay, so instead, on a hunch, I looked in the wastebasket and, sure enough, there was a wet kleenex soaked in his cum. He had used the pic to jack off too. He was not hot at all, so that wasn't too much of a turn on for me, but it was nice to know that I wasn't alone in jacking off to images of guys. Much later he confessed to me that he sometimes thought about guys, and I told him I did too. We never took it any farther than that. I later stood up at his wedding. He's still married.
The next year I was in another 6-person apartment (also with kleenex boy, though we weren't in the same room that year). I swear that 5 of the 6 of us were gay (and the 6th was questionable), but to this day, I'm the only one who is out. By this year I had discovered an adult bookstore in the nearest big city (Sioux Falls, SD), and I was the only one brave enough to go, but at some point in the semester each of the other guys, one or two at a time, maneuvered it so the two (or three) of us would go to Sioux Falls, and they'd ask me to take them to the adult bookstore so they could see what it was like. One of them decided to buy an issue of Torso, just because he thought it would be funny. (Yeah, straight guys do that all the time.) Another time one bought a bundle of magazines. On the visible back cover of one of the mags was a guy rimming an ass. You couldn't see the full body--just the ass--so you couldn't be positive it was a man getting rimmed, but I was pretty sure that's what it was. I, too, looked for a gay bundle that didn't look gay, and in the car on the way back to school, we opened our bundles and both of us were "shocked" to discover that we'd "accidentally" bought gay mags. He had been positive that was a WOMAN'S ass getting rimmed. Pretty flimsy, but we both played along so as not have to admit we really wanted the gay stuff. He's married now too.
Anyway, back to the cum rag part of it: bundle guy shared a bedroom with another guy, and I was in in the bedroom next door. One morning shortly after buying the gay mags, I heard someone go into the shower and come back out and go into the room afterwards. I thought it was bundle boy, and I waited for him to leave because I wanted to see if Mr. Straight Boy had used his gay mags to jack off to, but when he opened the door to leave, I saw that it was bundle boy's roommate. He was kinda cute, and he was a lifeguard at the local pool. When he left for class, even though it was the wrong guy, I still went next door to look for a cum rag, and I found a very freshly wet kleenex in the trash. I found the freshness of it to be a real turn on and I tasted it, which at the time I can't believe I did. I always imagined he'd used his roommate's gay mags to get off. That was the only time I found any of their cum rags, but I found a lot the next year with a different roommate.