This is a story about an au of mine, DVAtale. Where all monsters are either demons or angels. Sans is and incubus demon and Papyrus is an angel. Most monsters both demon and angel, go through heat. But the incubus/succubus doesn't. Well at least they're not supposed to. For if they do they're starved of energy and are in danger of dying. And today, Sans goes into heat.

Swapfell. What else shall i say.