Professor Severus Snape is a character from J.K. Rowling's "Harry Potter" series of books and films, and is also referenced by The Sorting Hat in the upcoming Scary Godmother x Harry Potter crossover.
History with The Sorting Hat
Although it is debatably non-canon, it can be assumed that at some point, Snape was having a secret affair with The Sorting Hat. At some point, The Sorting Hat had set his hat-like eyes on the Professor. However, Snape initially dissuaded his advances, as their kind of love was forbidden. In the end, Severus gave in to his seductive gaze, and the two had found themselves madly in love.
However, Professor McGonagall had caught the two lovers in the act one night. Although she kept the secret to herself, the damage was already done and the relationship tapered off shortly afterward. As fate would have it, Snape later would return the favor and was partially responsible for the break up between The Sorting Hat and McGonagall.