Hey, guys - fellow fetish holder here for girls gaining weight. I am not a psychiatrist but I have gathered a bit of helpful knowledge for this kind of stuff. First off, it's not your fault. You did nothing to start this, you didn't choose it and therefore are not responsible for the way you feel about whatever it is that turns you on.
The causes for fetishes are as best as we can scientifically prove unknown. Many believe it to be caused by specific events early in life, insignificant or significant, but the best support for this is based on case study. There is plausible theory that it could be genetic or happening in early neurological development as well. The main point to gather from this is - it doesn't matter. You have a fetish, it was caused by something, focus on dealing with it rather than wondering why.
Which brings me to my next point, which is rather unsettling - most of what I've heard is that fetishes cannot be 'cured' but rather dealt with. This may sound daunting, but depending on the fetish it can be very manageable.
Fetishes are harder on girls on average because it becomes more of a necessity to give in to a fetish in order to reach sexual satisfaction, but dealing with fetishism is varied and comes down to what works for you. A general rule is to find pleasure in relationships without the fetish if possible but be honest about it and don't be afraid to tell people about it if you think they will be mature and understanding about it. I think you'll find that most people once they understand that its not your decision to be turned on by it will completely understand and maybe even play along.
Liveinafantasy, I'm sure once you get a little older you'll find that someone will come along and stuff for you if that's what you like and they'd be happy to do it if it made you happy, its not as uncommon as you think

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