I can say in my situation, this was a huge part of it.
Trainer would promise us the world: money, lessons, shows, horses, even puppies. All in exchange for just staying at the farm a little longer, helping him with this or doing that. It snowballed into something that was almost cult-like: you felt like you HAD to be there all the time, either because you owed him or he promised you something and had yet to deliver.
While he kept me in his network of teenage girls, he never made a move on me. In my warped teenage mind, I thought it was because I wasn’t good enough, wasn’t pretty enough.
Now in adulthood, I think I was just too hard to groom. I had goals beyond what he could offer. My reason for being there was money— he paid me a lot (when he actually paid me, probably a grooming tactic to pay me inconsistently to keep me coming back). I used that money for shows and lessons in a different discipline. I didn’t want his horses, I wanted to do my own thing.
Everyone always asks “where are the parents?” to which I call BS. They were right there much of the time! They had NO idea. They did everything right. Their only mistake was trusting someone with a stellar reputation in his discipline.