Don't fuck Demons
Read the storyTracy, a futanari demon, falls in love with Jim the human. They live in their secluded cottage in the woods to avoid prying eyes, and spend their time being chaste yet romantic. However, Jim seeks a more intimate connection, but Tracy warns him that if they were to do so he would become a futanari demon like her. He accepts, and the two make love as her demonic traits overwrite his, replacing his human body with a form nearly identical to Tracy.