"She’s too old for you,” and she was right. Rarity was 22. He was 17. All the more reason that he loved her. She was a woman and he was just a kid. " A story of how Spike comes to terms with his love for a woman who he can't have, at least not now.
Spike has been waiting for a long time to gain the courage to ask Rarity to be his. His status as a Dragon Blood and his age stand in the way. Dragon Bloods are demonic dark and greedy, and that's how he saw himself. Not worthy of the beautiful Unicorn Blooded Rarity. He's waited so long for him to catch up to her in age but even then, Dragon Bloods and Unicorn Bloods don't become lovers. It's not forbidden, but very looked down upon. A high class Unicorn going for a lowly Dragon was unheard of. Dragons don't need Unicorns, they need gems and jewels. It's been like that for centuries, but Spike wants to change that.
Now taking on a new threat to Equestria, Spike is determined to protect Rarity no matter what the cost.