I would be careful not to identify yourself as a pervert. That's a thing you've done not a person you are. When people make the mistake of identifying themselves as under a condition, they tend to ingrain the concept that it's an inescapable part of themselves. Language is a powerful and subtle thing.

Perhaps as a tool to curb urges next time you're in a situation like this you could focus on your current responsibilities. For instance in the above situation you had a duty to your Mom to intervene when the boy in your custody was getting bullied. Now I know that hindsight is 20/20 and this is not meant to be anything but an object lesson for next time (i.e. this is not supposed to be a criticism and you shouldn't feel too bad given your current condition). But had you focused on said task you would have first of all stopped the situation that was negatively affecting you, and the boy would not have undergone undeserved pain. I've been in situations similar where due to my fetish I witnessed someone undergoing what I would have found pleasurable and I got turned on, unfortunately for the person who was experiencing it, they did not share my fetish and found what they were being put through disturbing and painful. In recent times I have learned that rather than living vicariously through them and taking pleasure in what is ultimately causing them to suffer, I can instead choose to empathize with the person, and do what I can to solve their problem. Because it's difficult to recognize that someone undergoing something that you fantasize about is actually bad, you can instead identify with the victim by, imagining that you were forced to undergo a fetish that someone else finds sexy that you don't (i.e. Homosexual domination ). If you can understand on a deeper level that that's what's going on then on a moral ground you should be able to push past you're own urges and help the kid (note: I referred to the kid a s a victim earlier and while it is indeed true that he's a victim of bullying, many would consider it an over-dramatization in the current discussion, however my purpose for identifying the boy as a victim is to help you to change your perspective. Identifying him this way gives you a way to empathize with hime where before you were crippled by your fetish and unable to act in a way that would have been good and right and upheld your responsibility to your mother). Anyhow, that's pretty much all I've got at the moment, I hope it helps. I apologize if this seems too judgmental, I actually don't care one way or the other about what happened in the story, that's in the past. My only goal was to encourage you to think in more critical terms about the morality of the situation. If you can change your mindset to such a degree that you actually get outraged at the fact that you got horny at what you were witnessing you will be that much closer to breaking free of these urges and enjoying something real in the not-so-distant-anymore future. Now for me it's really late, so I would certainly ask, that if I worded something in such a way that it makes little sense or that it seems offensive, please give me the benefit of the doubt and understand my intent is to help. I'm rootin for ya! :)