When Severus arrived at Hogwarts he and Lily were put into separate Houses. Severus went into Slytherin #myhouse! While Lily went into Gryffindor #HarryPotterVibe! Over the years though, Severus and Lily became best friends and are often seen hanging out a lot (books and movies!)

Severus excelled at Potions and often hangs out and/or with Death Eaters. Lily doesn't like this and often tells him about it.

Severus has always had a crush on Lily. Ever sense he first met her basically. (Dumbledore: after all this time? Severus: always)

Next chapter, Severus's Big Mistake