Disclaimer: Harry Potter belongs to J.K. Rowling. I make no claims to ownership.

Note:Some people think this is AU. The next chapter contains my reasoning for this story. It's not necessary to read it. The simple fact of the matter is that we know hardly anything about James and Lily, but they definitely inspired the people around them, which makes me think that both Lily and James were good people. Also, this does fit in with canon.

"Maturity is learning to walk away from people and situations that threaten your peace of mind, self-respect, values, morals or self-worth."

Toxic

When Lily was a child, she met a boy who was starved for affection. He had an extremely abrasive personality, but though it was hard, she tried desperately to remain friends with him. She thought that with a better influence in his life he might veer from the dark path he was already treading down.

She had seen his attitude toward Muggles. First he had insulted Petunia, and then he'd almost killed her by dropping a tree branch on her head. His treatment of her sister had poisoned her own relationship with Petunia. Then he'd thought it was funny when Mulciber attacked Mary MacDonald. Lily could not understand how he could hate her entire kind and what she stood for but still call her his best friend.

On their first train ride she defended him because he was the only friend she had in this strange new world. Later, though, she realized that Severus antagonized nearly everyone he met. That trend became fairly common any time she introduced him to someone new, and most of her friends were urging her away from him after seeing how he tried to control her.

After their O.W.L. exam, it was for the sake of their childhood friendship that she again went to his defense. She still cared about him, even if his intense feelings for her were disconcerting.

"You think you're funny, but you're just an arrogant, bullying toerag, Potter. Leave him alone."

She knew that was wrong. Potter only got into fights with people who antagonized him or threatened other students. That was why he remained popular; he didn't just protect his friends, but other people, too. The only one she had ever seen him bully was Severus.

Then Severus grabbed his wand, and blood splattered across Potter's face. Lily stifled a gasp and made to draw her own wand, but Potter was quicker and suddenly Severus was dangling in the air, his robes falling over his head and revealing his underwear.

Her lips twitched. She knew it was wrong to laugh, but it really was quite funny, and other than being embarrassing, it was harmless. Lily had seen Severus do much worse to Potter and his friends. Just now was an example.

This had to be stopped before Severus did something more drastic.

"Let him down!" she shouted.

Potter, ever the show man, let Severus drop onto the ground. Severus immediately leaped to his feet, a snarl baring his yellowed teeth, but Black stopped him from attacking again.

"LEAVE HIM ALONE!" Lily cried, scrabbling to take out her own wand.

Potter and Black looked at her. They were both better duelists than her, and knew far more spells, but she could be creative with her attacks.

"Ah, Evans, don't make me hex you," said Potter.

Lily knew it wasn't a serious threat. Unlike Severus' friends, Potter never attacked a girl.

"Take the curse off him, then!" she demanded.

After another long moment, Potter finally obeyed. "There you go. You're lucky Evans was here, Snivellus – "

Lily stepped forward to help Severus to his feet.

"I don't need help from filthy little Mudbloods like her!"

She stopped and blinked. Her mind seemed to slow as it processed that he had finally crossed that last line. Just the other day she had seen him laughing with Avery and Mulciber, who both had made it clear they intended to become Death Eaters and wipe out her kind, but until now she had convinced herself he was agreeing with them only in appearance. It seemed she had been wrong, though.

Lily realized that Severus could not be saved. He was too far gone, too deep into the Dark Arts.

"Fine," she forced out. "I won't bother in future. And I'd wash your pants if I were you, Snivellus."

Sometimes, a friendship was too toxic and had to be let go.

AN1: Dear readers: If you're ever in a relationship like this, whether with a friend or a partner, get out of it. I know you want to stay together, but you can't save everyone.

AN2: This has been rewritten. Hopefully it explains Lily's thoughts a bit more.

AN3: READ THE NEXT CHAPTER IF I DEEPLY OFFENDED YOU WITH THIS!