This is such a great question and the stories so far have been so fun to read. I'm sure I have more of these, but two are coming to mind right now. They are not as notable as some of these responses, but they fit the criteria at least.
Incident #1
As a child, one of my neighbors was around my age and was my best friend. We often hung out and played together in our rural neighborhood and at my house, but seldom at his. That was mostly due to them being caretakers for a few family members that lived with them and I'm sure they didn't need the additional burden of more unruly kids running around their house. Anyway, he had a much older sister who I thought was cute. Because of our age difference and my visits to their house being few and far between, I saw her very infrequently, but always fantasized about tickling her. She had kind of a unique laugh and I had wondered what it must be like when she's tickled. Was she even ticklish? I was way too shy about tickling to attempt something like that, especially on her, and even more so because I usually only ever saw her in the company of several other people.
Well, one day, I was at their house for a special occasion. I think it was a birthday party or something. I remember sitting in the living room on their sofa, feeling slightly out of place since there was some of his extended family there that I didn't know very well and everyone else was connecting on that level that only close family usually can. In addition to his immediate family, There were a few grandparents, some cousins, an aunt, and the one crazy uncle everyone seems to have. At one point my friend had to help his dad with something for several minutes, so I just sat there listening to old people talk about old people things and eventually just kind of zoned out for a minute. I was snapped out of my haze by a shrill feminine scream followed by loud laughter on the living room floor right in front of me. I quickly turned my head from whatever space I was staring off into, and focused all my attention onto the floor. Wait, I know that sound, I thought to myself. Sure enough, there was crazy uncle on top of my friend's sister with her arms pinned above her head being tickled on the floor!
Now, when I say she was being tickled on the floor, I'm not talking about a 10 second playful tickle, or even a minute long you'll-pay-for-that kind of tickle. No. I'm talking about one of those the-only-way-I-can-summon-the-dark-lord-is-through-this-sinister-ritual kind of tickle that lasted several minutes. To this day, it is burned in my memory as one of the most brutal ticklings I've ever seen. He tickled her ribs, tummy, and underarms nearly without ceasing, and she bucked and howled with such forced laughter and screams that I thought she would pass out. I didn't say or do anything, in part because I was just so transfixed by this impossible thing that was happening in front of me, but also because I didn't want to jinx anything (not being superstitious be damned!).
When it was over, I was left so delighted at what I had witnessed, that I remember virtually nothing else from that day. However, I was left with several questions that still linger in my mind all these years later. What started all that? Does this happen often? How did it start so suddenly? I know I had zoned out a bit, but I thought I'd have a least picked up on something that lead to it. Why was everyone so absolutely cool with it to the point that they basically didn't even notice? And most importantly, WTF? I don't recall ever seeing her tickled again. Though I did try to find opportunities to tickle her myself, I never got the chance.
Incident #2
Just a disclaimer for this one, there is no actual tickling, so don't get your hopes up! Several years ago I worked in an administrative office setting with fairly strict policies due to the serious nature of the work. The workplace culture was generally very reserved and professional. The vast majority of my coworkers were middle-aged women, who occasionally took joy in teasing me, their young male colleague. The teasing had never really been very risque or anything, but did usually involve humor around me being very outnumbered among all the women at the office. It was all in good fun and I enjoyed the playful banter from time to time.
My workload was heavy and I kept to myself most of the time, in part because I probably had less in common with most of my coworkers, but also just to stay afloat with all that had to be done. I became known as a shy, quiet guy who took work very seriously, and for the most part, I'd say that was fairly accurate in that environment. Most of the meetings I was involved in were dealing with other departments or broader organization meetings where many more extended coworkers were present (those outside of the admin offices). Meetings for just the admin staff themselves were less frequent to favor efficiency. Occasionally we would have a somewhat relaxed meeting with select admin staff to go over broad status reports and all manner of boring things. In those meetings, there were typically about 8 - 15 members present, me being the only male.
For one of those admin meetings, I got there a little early, so I was one of the first to arrive in the small conference room. I had a bad headache that day and was feeling even less talkative than normal. I mostly just acted like I was busy to avoid small talk while a few people came in and sat down. I immediately noticed that one of the women attending the meeting, I'll call her B, was an admin staff member who I had only very rare interactions with because she was usually doing evaluations off-site. She was a very confident, fit woman in her mid-50s who was always very talkative with everyone, so naturally I often avoided her lol. Anyway, she sat down in the chair next to me, though our two chairs were still spaced pretty far apart. She said "hi" as did I, and then I pretended to go back to thinking about something important. There were maybe five people in the room at the time, mostly just staying quiet and waiting patiently for the meeting to start. We sat there for a minute longer and she said to me "you're quiet." Nothing I hadn't heard before, I thought. Before I got out a clever response, B asked the rest of the group, "isn't he quiet?" Now hold on, I thought to myself, everyone else is being pretty quiet, too. A few of the others kind of smiled or chuckled.
At that moment, B looked right at me, but spoke to everyone else, and said–and I shit you not–"I bet he's ticklish!"
I didn't move at all. My body seized up and I turned to stone. The intensity in which she said those words still haunts me to this day. I felt my blood temperature rise a few degrees and my throat was so tight that I felt like it would burst–there was no way I could speak. Sure I couldn't move, but my soul left my body and fell onto the floor. There was no time to react, even if I weren't paralyzed. B then asked, "do you guys think he's ticklish?" One of them said, "hmm, maaaybee" in curious tone, while another said "yeah, I think so," in a way that sounded like she was testing the idea in her mind. B then affirmed that with, "yes, I think he is ticklish. I bet if I tickled him on his ribs he wouldn't be so quiet! Are you ticklish?"
Everything was going dark. Was I going to pass out? Was this the cold hand of death around my throat? Oh my god...is she going to tickle me? More people moved in and closed the door. It's all fuzzy after that, but basically she got distracted right after that by the other staff coming in to start the meeting. I want to say I at least smiled at her and nervously laughed it off as I was having my out of body experience, but I honestly don't know. What a wild thing to randomly come up in such an unexpected place. It never came up again with anyone in my workplace, to include with B.
