My earliest memory of sexual feelings was around 5 years old, our pre-school took a field trip to a pool facility to get swim lessons, the "swim coach" told us to just remove our clothes and leave them on the bench in the locker room, , he didn't want us to put our swim suits on because at our age, it was just a waste of time.
When we lined up and paraded out of the changing room, I apparently was fully aroused, he sat us all on the side of the pool, but noticed my excitement and told me, "oh, you're one of those" and told me before any other interactions with others, you need to work on your kicking, and quickly placed me in the water holding the side of the pool and told me to keep kicking while he gave us instructions.
That same year, we had a family day at the beach, I went to the restroom, and there were open showers, there were a bunch of naked men showering, after I peed, I decided, I wanted to shower too, so I stripped down, with a bunch of strangers to shower off, again, I was visibly excited. One of the men said, look he's one of us, and proceeded to fondle and perform about 30 seconds of oral on me before another man beat the hell out of him and told me to get dressed and never come back without a family member...
After that, my sexual exploration continued on a very regular basis...