Sour

This is a little drabble I made for the daily prompt on Reddit, which was "Sour." I hope you enjoy!

Whenever Undyne thought about the day she had fought Frisk, the memory of her own actions put a sour taste in her mouth.

She had been so cold, so cruel, so angry, throwing out hateful words as easily as she had deadly spears as she stared into Frisk's terrified brown eyes. Frisk had begged and pleaded, but she had still tried to kill them, had repaid their kindness with cruelty and pain.

She had been considered the hero of monsters; how could she have behaved so much like a villain?

How could she have hurt a child? And how could she have told one that their very existence was a crime? Frisk had done nothing to harm anyone, but Undyne had still persecuted them like a common criminal.

She had been horrible, and yet Frisk had still saved her, had poured water on her after she collapsed when she chased them into Hotland.

Despite everything she had done, Frisk had forgiven her, had become her bestie, had drank tea and had a cooking lesson at her house. They had even delivered her letter to Alphys and helped get them together.

And then they risked everything to get the monsters to the surface, after everything the monsters had put them through.

...

Undyne glanced to the small child that was now cuddled between her and Alphys as they watched an anime, and wondered if she even deserved all this.

Frisk never mentioned their fight, but sometimes when Undyne moved too fast or made a sudden arm motion, they would flinch away for a moment, then act like it had never happened.

Sometimes Undyne would catch Frisk watching her with sadness and regret in their eyes, and she never understood why.

Frisk didn't deserve to go through any more pain.

Undyne couldn't take back the past. But she would do everything she could to make it up to Frisk. She would give her all at being the bestie Frisk deserved.

And someday, maybe she could give Frisk enough sweet memories to make the sour ones fade.