You are Dean and Castiel’s daughter. You live in a house not too far from the bunker. You suffer from depression, and both of your fathers are at a complete loss for how to handle it.
Sam is fourteen. You are sixteen. Dean is eighteen. You are the third Winchester sibling, older than Sam but younger than Dean. Sam comes to you, coming out as transgender, terrified about how you and the rest of the family will react.
Y/N hunted with the Winchesters for many years. When they were turned into a vampire, they did their best to stay a hunter and not hurt innocents. Eventually, they and Dean fell in love, and conceived twins. Y/N died before the twins were born.
Cas and Dean are a couple, and they are… freaky. Y/N, a vampire hunter with super hearing, can hear everything as Cas fucks Dean, can hear all of the dirty talk and breeding kink happening.