Harry started at Wormtail for a moment, then back at James, who was now doodling on a bit of scrap parchment. He had drawn a snitch and was now tracing the letters 'LE'. What did that stand for?.....hastily crossed out the 'LE' he had been embellishing....stuffed his quill and the exam paper into his bat.Order of the phoenix ch.Snape's worst memory. P567 uk. (Where James shows his interest in Lily Evans) 

 Snape lay panting on the ground...Several people watching laughed; Snape was clearly unpopular.' You wait,' he panted, staring at James with an expression of purest loathing.....'Leave him ALONE!...Leave him alone, Lily repeated. She was looking at James with every sign of great dislike. 'whats's he done to you?... You think you're funny,' she said coldly,' But youre just an arrogant, bullying toerag, Potter. Leave him alone.' Order of the Phoenix ch Snape's worst memory p571 uk. and a few pages of similar, where Snape also gets mad at Lily, possibly for saving him, or possibly for seeing him humiliated.