Her leaving Snape wasn't a sign of her being a bad friend but rather that their interests no longer clashed as he was studying something that Lily despised. They just grew apart over time, and that was no fault of Lily's. Did Lily Potter ever forgive Severus Snape before she died? No, she definitely didn't.
Snape calls Lily a Mudblood, Lily tells James that she would never date him because he's an egotistical jerk. Later, Snape tries to apologize for calling Lily a Mudblood, but she's not interested; she ends their friendship due to his association with Death Eaters.
They Stayed Best Friends Until Fifth Year. Lily and Snape were inseparable friends who only parted ways in their fifth year when he took a turn down a dark path, opting to pursue the Dark Arts against her wishes. That may also be the year Lily responded favorably to James's advances.
One day, Lily tried to help Snape while he was being bullied by James. In response, he called her a 'Mudblood' and they stopped being friends. James attempted to apologise to Lily later that day but she did not accept it.
Towards the end of The Deathly Hallows, we learn Snape apologised later on. Unsurprisingly, Lily didn't forgive him and severed their friendship permanently.
The fact that Lily chose James Potter, Harry's father, only fuels Snape's hostility towards Harry. Snape's character has been widely acclaimed by readers and critics. Rowling described him as "a gift of a character" whose story she had known since the first book.
Lily brought light and warmth into Snape's life from the moment they met. He was an isolated, lonely child whose magic would have only made him more of an outsider in his hometown of Cokeworth.
Now, as firmly established, Snape was not the greatest fan of Harry, but that didn't mean that he ever stopped loving Lily. Dumbledore was surprised that Snape seemed to care for the boy. With a swish of his wand, Snape conjured up a Patronus – Lily's Patronus, a doe. 'Always,' he said.
As Rowling explained in a series of tweets, Snape loved Harry's mother, Lily, and his unrequited affection drove him to resent Harry's father, James — and by extension, Harry himself.
When she found out her best friend, Teresa Berlitz, was dating James' best friend, Sirius Black, Lily's hate for James decreased slightly. Slightly. In her 5th year she was made a prefect alongside Remus Lupin. The two of them did nightly patrols of the halls together resulting in a friendship between the two.
To be fair, James would (and did) willingly die for Lily too. But Snape loved Lily so much that he was willing to die just to avenge her. He would die just for the memory of her.
He Called Lily A Mudblood
Even though Snape repeatedly tried to apologize for his mistake afterward, it became clear that it was yet another incident that had done irreparable damage to their friendship.
They were close friends, she saw in him someone special that she could care about. But she couldn't be with him. So, it seems like it was very unlikely that Lily ever found out Snape loved her.
“Oh, Harry, James actually regretted bullying Snape a lot. He always wanted to apologize.”
Ultimately, Snape was punishing Harry for being James son, and himself for Lily's death. Revealing how he felt about Lily, might expose him and her to more danger from Voldemort. He had to hide so many feelings in order to be a good double agent.
The acclaimed author explained that Harry paid tribute to Snape because of “forgiveness and gratitude.” Though Snape bullied Harry, he also saved him. “Harry hoped in his heart that he too would be forgiven.
Draco Malfoy's mother Narcissa was cold, cunning and devoted to the Dark Lord. But she was also a mother, which meant she was willing to risk everything to make sure her son was safe. When Harry survived Voldemort's Killing Curse for the second time, Narcissa pretended he was dead so she could get to Draco.
He'd have a hard time convincing his Death Eater friends not to kill her and she'd spend a lot of time hanging around with people who'd discriminate against her blood status. They could potentially have a child, but Snape doesn't seem like the person who'd want one to me. So I'd assume they'd have a childless marriage.
Knowing that Snape has been on the Dumbledore's side for all seven of the Harry Potter books reveals him as an extremely brave man and a truly skilled spy. Snape has had to face and deceive the terrifying Lord Voldemort constantly.
Dumbledore reveals how thoroughly he loves Harry. Harry is brave, and Dumbledore is proud as any father would be. More than that, Dumbledore succumbs to a parent's weakness; he cares more about Harry's happiness and wellbeing than the wizarding world he is trying to protect.
When Snape heard the prophecy and pleaded with Voldemort to spare Lily's life, he may have inadvertently caused his downfall. While we know Voldemort killed Lily, he did give her a choice. If she stepped aside and allowed him to murder Harry, he would spare her. Lily refused and sacrificed herself to save her son.
Snape is distraught by Lily's death, and Dumbledore tells him that her son survived – and that his eyes are just like hers. Snape agrees to help Dumbledore protect Harry, even though he's James Potter's son too, on the condition that nobody ever find out.
He said, 'According to Victorian flower language, asphodel is a type of lily meaning “my regrets follow you to the grave” and wormwood means “absence” and also typically symbolises bitter sorrow. If you combined that, Snape's words mean “I bitterly regret Lily's death”.
He hid them using the only thing that would work against Voldemort. He used Fidelius charm and after that even secret keeper was to be protected using that as Sirius said in PoA. The plan failed because wormtail who was their secret keeper betrayed them.