The Blood is Compulsory

Simin is a priestess of the goddess of order; as such, she seeks to live a virtuous life, and abides by the greatest taboo of her culture: you shall not spill blood. Aurum is a priest of the god of blood; as such, he honors his faith in the only way there is: by regularly gifting his own blood as an offering.
Naturally, the two of them despise each other. But when two of their followers wish to get married, they're the ones called upon to find a way to make a wedding that will honor both their gods. Will they manage to set aside their differences for long enough to achieve their goals... as well as, perhaps, an understanding?
(A 10k words-long M/F erotica story between a trans woman and an asexual man.)
This book features ritualistic self-harm and blood play. Reader discretion is advised.