When Pigs Fly

MAIN STORY FINISHED, ADDITIONAL MATERIAL STILL BEING POSTED
Severus had always believed that romance wasn't for him. Everyone else believed him to be filthy death eater scum, and he agreed, never fathoming the concept of someone liking him enough to actually pursue a relationship with him.
Until one fine day in sixth year, when he finds himself with a small, three year old child clinging to his right leg, calling him Papa.

Cross Posted on AO3 under MoonlightEtherealAria