Well actually, you are harming yourself because you are reinforcing your attraction to things that are illegal and abusive.
As explored earlier, we can get pleasure from our fantasies. If the subjects of our fantasies are inappropriate, we then associate feelings of pleasure with something that is illegal and abusive. This is particularly true if you masturbate to the point of ejaculation to the fantasy, as the next time you think of the fantasy you will remember the pleasure and arousal.
This is not helpful if you want to control an attraction to children or an illegal behaviour such as looking at sexual images of children.
So what are appropriate and inappropriate fantasies? We split inappropriate fantasies into three sections:
Illegal fantasies
These are fantasies that would be illegal if they were carried out or acted on in real life, such as having sex with a child.
Abusive fantasies
So, imagine you are a 48 year old man and you are having a sexual fantasy about a 16 year old. Is this illegal? No. But is this appropriate? We think not, because there is likely to be a difference in power, whether that be related to age, money, or life experience.
Not OK for me
This could be a legal and healthy fantasy for some people, but not for you. For example an adult dressed as a school child. This may be ok for some people but for those who have a sexual interest in children, it may take them a step closer to a fantasy about a child.