A taboo for some is having sex with a man of the cloth. A Catholic priest is really the only one here a woman would be falling for, since other forms of Christianity allow their men of the cloth to take wives. Rabbi’s and ministers are allowed to marry, but as priests take a vow of celibacy, it’s not allowed.
There was a very popular book and miniseries in the 1980’s called “The Thorn Birds”, about a priest that fell in love with a woman, it was quite big in its day, forbidden love and all that. The thought of stealing a man away from God himself holds appeal to some women, that they alone could be the most tempting thing this man had ever known. Men don’t join the priesthood in the numbers they once did, it’s been on the steady decline since the 1960’s, and men have been leaving once they have joined because they cannot take being alone. Love and sex is too much of a draw. They want a family and if they want that, it’s crazy to deny themselves.
Not as many men have the fantasy of nuns it seems. There has only been one client I ever had that had a fantasy about priests and nuns, he was a character for sure. He wanted the nuns getting it on together and the priests and nuns to be getting it on together, his stuff was pretty wild. I’d think only one raised in the church would likely have such fantasies, as why would an atheist bother thinking of such things, they likely wouldn’t. I’m sure some have, but not as many as the ones raised around nuns and priests would, and their fantasies would be a rebelling of sorts.