Artist’s description from DA:

Poor Big Macntosh had his leg blown off in the final battle of the First Great War. He was shipped home to a very eager Granny Smith and Applebloom.

Physical therapy was tough for him, especially accepting the fact he’d never participate in another apple bucking season. That and he was in a lot of pain when he was trying to adjust to his giant, bulky prosthetic.

He would often go to Fluttershy for help and medication, since he was such a big stallion and required a large quantity of painkillers. Over time he found himslef visiting her simply for her company. They could spend hours in her house, saying nothing at all, yet perfectly contented.

One day there was a tornado warning and Flutters didn’t want to risk Big Mac getting caught up in it and being injured. She had him stay the night.

He heard her crying out loudly in the middle of the night, pleading and sobbing. He stumbled up her stairs to see if she was ok.

That night she had a nightmare of a traumatic event that happened while she was overseas in Zebrica.

He also confessed that he had grown attached to her, and that as long as he was still knockin’ around, no pony would hurt her ever again.

The two began a steady relationship (much to his sisters’ and grandmother’s pleasure) and to prevent him from straining himself on walks to and from Fluttershy’s cottage, he moved in shortly after.

Fluttershy helped him set up a sizeable garden of easy to care for crops so he could keep himself busy while she was working away at her General Clinic. He also made it a point to be a stay-at home-dad when their adopted daughter Hazelnut came about. He promised he’d always be there for her (obviously beacuse of his parent’s absence during a good protion of his life).