A/N: Drabble about how Severus and Lily dealt with the end of their friendship.
The following weeks after their falling out - after the incident, were the most painful. Severus used every opportunity he could to apologize to Lily. He asked for her forgiveness before Charms and Potions started, he asked if they could talk when he spotted her eating in the Great Hall, ignoring the jeers her friends threw at him as he approached. Severus even sent her letters via owl, saying how he wish he could take it all back, that he wanted to be friends again. Most nights his self-hatred prevented him from sleeping. It was a mistake, a stupid mistake, but Lily had made her choice. He didn't blame her.
The first few weeks were just as hard for Lily. Her best friend, the one who introduced her to magic and all its' wonders, had broken her heart. The friend who told her when they first met that her being born of a Muggle family didn't make any difference had lied. As much as she tried to ignore the signs, she knew that they were growing apart, she knew his love of the Dark Arts was going to put the nail in the coffin. She knew it was coming, and it still broke her heart. The night he called her Mudblood, she cried herself to sleep. She cried at the cruel thing Severus had spat at her, and she also cried at the loss of her best and most cherished friend.
At each opportunity, Lily could have forgiven him, and at each opportunity she wanted to. Lily tried to lead Severus back to a better path, one without Dark Magic and being around Death Eaters of the future, but he was too far gone. Only he could save himself, and if she took him back nothing would change. The best option was to cut him off, and it was the hardest decision she ever made.
Soon, weeks turned into months, and Severus's apologies became fewer and fewer. When passing in the hallways, if they locked eyes, Lily's would shift away immediately, whereas Severus would look on at her with a sad kind of hope. If they were made to partner up in class, Lily would say only what was necessary of her, not even answering if Severus began to resort to talking about the weather. Severus was never one for small talk, Lily knew this best, but he dug up any mundane topic to talk about if it meant he might get a conversation out of her. It never did.
As the months passed, Lily began to heal little by little. She made new friends even though none compared to her best friend. Severus was beginning to find sleep again as he resigned a little more each day that Lily wasn't going to take him back. Severus spent even more time with fellow students who studied the Dark Arts with the intention of getting Lily off his mind. It worked – most days. Other days, Severus would pull out his wand to practice a hex and he'd hear her voice telling him how she knows he can do better than this. Some days, his self-hatred was so enveloping that he wondered if it was best for everyone if he just offed himself.
Eventually, the apologies stopped. As they entered their sixth year, their paths diverged moreso. Lily had kind, new friends, and Severus spent half of his time at Hogwarts alone completely or amongst other students planning to join Voldemort after graduating Hogwarts. By their seventh year, Severus and Lily had no classes together at all and barely passed by one another in the hallways, which Severus was both saddened by and grateful for; as he saw his best friend less, but also did not have to be subjected to seeing her holding hands with James Potter.
On their very last day at Hogwarts, Severus mustered up the courage to give it one last try. He would give Lily one last apology, and if she rejected him he would never bother her again. Severus couldn't believe that it had been two years since they had had their falling out. Those two years felt like a lifetime ago, and sometimes they both wondered if they had really been best friends, or if maybe it was just a story they made up.
On their last day at Hogwarts, when all exams had ended but it was not quite time for the feast and the awarding of the House Cup, Severus set out to look for Lily. He found her outside the castle sitting under an old oak tree, her hair like fire under the light of the setting sun. The tree was one they used to sit under together when making fun of James Potter and his friends or studying for their next exam. Severus began to set across the field when he saw her stand up, and as he came closer he saw that Lily was talking with someone, but with who he did not know. The trunk of the tree was wide enough to conceal the other person's figure.
Lily tugged her companion away from the tree and into view. She pulled him into her arms and gave him a kiss on the cheek. James Potter.
Severus stopped in his tracks and watched as James kissed her back, this time on the lips. When they pulled away, Severus saw Lily giggle and whisper something. Severus looked at the grass beneath him, the shadows of the blades becoming longer and stretched as the sun inched ever further below the horizon. He then gave a small nod to himself and turned back toward the castle.