The Perks Of A Brilliant Bet

Hogwarts AU crossover, (Supergirl/Once Upon a Time) mainly Supercat/SuperCorp and Swan Queen but also some Supercorp and Rumbelle, maybe even a little Sanvers.

Gryffindor's Emma Swan, Slytherin's Lena Luthor, Hufflepuff's Kara Danvers and Ravenclaw's Belle French, are the new female prefects of Hogwarts school of witchcraft and wizardry, all excellent students and the most promising witches of their age, until they start sharing the same Prefect's bedroom and their friendship becomes a pain for more than one professor of the school. Potion's professor Mills, DADA's professor Gold and transfiguration's professor Grant are the first to regret the decision when they get involved romantically with the new prefects, thanks to a bet between the girls.