I went to Typhoon Lagoon in Florida when I was about 12. I was in the wave pool, and swam right up to the wave generator so I'd get swept back by some of the biggest waves. I was getting thrown a good 20 feet backwards along with everyone else, it was awesome.
One wave hit me, and I went drifting back quite a distance. I felt something brush past my leg, assuming it was someone else, or whatever. The place was packed, so I didn't really think much of it. I stood back up in the water, and realised it was a pair of swimshorts, floating on the surface. My swimshorts. I looked down, and saw my pecker was out in the open, being gently lapped by the waves. Luckily at this point the water was at waist height so not too much of my junk was visible, but everyone around me knew. They watched me scramble for my swimshorts and laughed.
I left the pool in shame. It genuinely ruined the rest of my day - I was afraid of being recognised around the park as the kid that lost his swimshorts. I just wanted to go home