Back in 1995 I wrote Love Thine Enemas and Heal Thyself, and expanded it through five editions to do just that. From years of doing enemas, and studying them, the fantasy related to sex is about 90% women, 10% men, but for both it is hard to share because of all the enema phobias, and the natural solitariness of colon functions.
And with fantasies, there is the additional problem that not all fantasies are alike. Over several years of research on line talking to people about their enemas and fantasies about them, I identified twelve variables. Overwhelmingly men play the little boys, are into receiving them from a "Mommy" figure. Women split, far more women than men are into giving than receiving, and in health care you find about 95% of colon therapists are women, and about 90% prefer a female therapist.
In any case, that book has twelve embedded enemas described in detail to fit most safe fantasies, and is relatively well written. A coffee table book, you need only earmark your fantasy and let your partner read it. I don't know how many people have thanked me for this, but it is in the hundreds that have used the book for this exact purpose.
The same is true for stories on line, and perhaps even better. I gave people a choice of twelve basic fantasies in the book. There are hundreds of stories on line with variations to match a rainbow of fantasies. And that is the problem. Each person with a fetish has mental pictures, and the possibilities are endless, so what is a turn on for 50% of those having a fetish, will turn off others.
another advantage is lack of exposure to yourself. To share inner feelings with a mate can be dangerous. If you talk too much, they know and can hurt you. It is why many people prefer to pay someone that they can talk freely too, use an alias, and keep private thoughts private.
Sharing a book or paper is safer, you can bring it home and show them what you found on the subway seat next to you on the way home. "Isn't this weird," you say, then try to guess their feelings as they read it. If they cringe and throw it away, you don't have to say more. If they keep reading every word then go back to the sexy stuff, you may want to read with them and say, "I guess this ain't so bad---wanna try it?" and you aren't exposing yourself in a way that will hurt you, and it can open something up.