HP Has Clearly Found Someone Who Fell in Love at First Sight

HP, main character is the bottom, Snape is the CP (couple). Warning: [Dual male leads, some love-first-then-love story elements]. [No negative portrayal of any house, and I personally really like Lily.] Carl is a recently graduated professor of Dark Arts from Durmstrang, having blown up half the school building with his alchemy—a truly disastrous mistake. Upon returning to England, he receives an invitation from Hogwarts. Considering it's likely they want him to continue in his old profession, Carl initially wants to refuse, but Dumbledore offers him an offer he can't refuse: a professorship in Alchemy plus a letter of recommendation from Nicolas Flamel. Carl readily agrees and randomly chooses an inn in Hogsmeade the day before, expecting to start work smoothly. But then, an unexpected incident occurs: a love potion mix-up leaves him tightly bound to someone. However… Carl says, he doesn't dislike her, he even likes her?