@OP: If you can’t be bothered to copy-paste the story, at least tag story in the comments.
 
From the source:
 
Amber sat on the mattress in his new quarters in the Stable and pondered his change of fortune.
 
A couple of days ago the pony-dragon hybrid had been fishing for something that wouldn’t eat him instead in wastelands. The sound of nearby gunfire had drawn him to what was obviously the aftermath of a raider ambush. Not an uncommon thing out here, but a couple of things had caught his attention.
 
First, the raiders had left a survivor. More important they’d left the survivor in possession of all their limbs.
 
Second, the survivor was obviously a Stable Dweller. It wasn’t just the fact that the stallion had one of the distinctive suits; it was the fact that it and everything about the stallion was cleaner than anything had a right to be in the wastelands.
 
Fearing the raiders might return and finish the job, and possibly him in the process, Amber had lugged the semi-conscious stallion away to a hideout he had set up nearby. Over the next 24 hours he tended to the stallion’s wounds until lucidity return to the survivor.
 
Much to Amber’s surprise he learned that there was previously unknown Stable nearby. The stallion was surprisingly not taken back by Amber’s mixed heritage. He seemed genuinely grateful to him. Enough so that he extended an invitation to visit his Stable.
 
Amber looked around at the room that had been given to him during his visit. Everything looked odd to him. Everything was too new, too clean, too fresh. The air coming from the air ducts had none of the musty smells he was use to. The water from the faucet in the bathroom sink was crystal clear. The linens on the bed he sat on didn’t feel like they’d been passed down by 4 generations. Was this what the world had been like before the war?
 
His quarters included the bed he was sitting on. A desk with a terminal and obligatory desk lamp. Primary illumination was provided by light panels in the ceiling. He had a couple of chairs, a dresser and foot locker at his disposal. Along with his own bathroom with a sink, toilet, and combination shower and tub.
 
He’d just finished his mental inventory when he was startled by the sound of the doorbell to his quarters ringing. Rising he went over to the door, and after a couple of seconds he found the correct button to open it. Standing in the hallway was white female unicorn dressed in one of the obligatory blue Stable suits. Although she looked better in it than the stallion he’d rescued had. Although now that he thought of it he hadn’t seen any other stallions since he’d entered the Stable. Just mares.
 
He was still attempting to grasp the meaning of this visitor when she spoke up in a happy, effervescent voice.
 
“Hello! My name is Sweetie Belle! I’m the Assistant Entertainment and morale Mare here at Stable 69! Our stallion told me about your arrival. So I’m here to say Hi and to welcome you to the Stable! Also I need to explain a couple things to you. May I come in?”
 
Recovering from the mare’s enthusiastic introduction Amber welcomed her into the room. Closing the door he turned to find the mare looking him up and down intently.
 
“Well! We’ll get you a suit while your garments are being cleaned, sanitized, decontaminated, and mended. Let me tell you about the other services this Stable has to offer along with its rules and regulations!”
 
What followed was a blur as over the next hour the mare explained how things worked at Stable 69. However she was particularly emphatic about conserving water.
 
“We have an almost zero-loss recycling system but water is still a very precious resource here, so we make every effort to conserve it. Please keep that in mind and try use it wisely!”
 
The stallion grinned. “Any suggestions from the Assistant Entertainment and Morale Mare?” He got up and removed the battered leather vest he was wearing and started hanging it up on a hanger. The climate control was keeping the room warm enough to make it redundant.
 
“Don’t leave faucets running. Report any water leaks to Stable dweller, and don’t take overly long showers.” Said the mare as if she was remembering a checklist.
 
Amber finished hanging the vest. “Any other suggestions you…” His voice trailed off as he turned around. Sweetie was standing in front of him and was in the process of slowly unzipping her suit.
 
“Well communally baths are a great way to save water and you’ll need one before your medical exam!” Sweetie giggled. “Welcome to the Stable!”
 
I am going to be doing some anthro MLP/Fallout related art for :iconskyline-twilight: as patron rewards with his OC Amber, Sweetie and other MLP characters. So I did this as a study piece and this is story that popped into my head as I did it.