When I was a child in Singapore my mother used to take us to the swimming pool at the local RAF base most days and there was a man there, one of the RAF offcers, I think, who used to enjoy joinng us children like some adults do, but he used to focus on me and pick me up in the pool to throw me further, but always held me close and I could feel --- well, I didn't know what hard between my legs.
I really felt uncomfortable about it, but didn't know what or why, so didn't tell my mother, but whenever he got into the pool, I got out and went to sit with her. He would come over to me to encourage me to come back into the pool, but I never went, and my mother never encouraged me.
He never showed any interst in my youger sister. I was long, thin and just pre-pubescent, whils she was younger and more 'cuddily' in shape
Many years later I mentioned it to my mother and she said that she had had a similar experience when she was a child, sent to collect her mother's medication from the doctor's surgery. He would sit her on his lap and give her a cuddle, which always made her feel uncomfortable. if I could have told her, she would have made sure that he did not come and bother us in the pool or out.