Eldritch Futanari
A romance/erotica trope in which a character who is a futanari (a woman with both female anatomy and a penis) is also an eldritch being, cosmic entity, or something equally inhuman and reality-bending. The story plays on the awe and horror of encountering a lover whose body and existence defy human norms.
Readers love the collision of intimidating cosmic power with intimate, explicit anatomy, letting them enjoy both the thrill of the unknowable and the satisfaction of a body that can deliver very human pleasure. It offers a way to explore consent and surrender with a partner who is literally beyond comprehension, which heightens the stakes of desire and trust.