Days later Mark was grazing in a pasture. Doctor Downway had given him the okay that he was a perfectly healthy pony. There were others who had also been transformed but Mark was the only pony so he didn't have much contact with the others.
It had taken him a while to get used to being a pony and to relearn how to talk. He mostly got clinical treatment which was uncomfortable but tolerable. There were no toilets for ponies so Mark had a special stall designated for him so he could at least have some privacy. He tried to wear clothes but he couldn't dress himself and the clothes didn't do for him what he wished they would.
Doctor Downway came to visit him and Brad, his parter on the FBI, was with him. "Okay, it's time to talk seriously about what to do now. You're stabilized so we could try to turn you back into a human but I have to warn you, it is risky. Thirty-seven people were exposed to nanites and twenty of them died. Among the survivors, some only had partial transformations becoming anthros. I would recommend that you think about this for a while. Don't make a decision until you've given being a pony a chance. If you wind up an anthro, you're life would be more difficult than it is as a pony. You'd be stuck between worlds suffering the disadvantages of being a pony in a human world plus the disadvantages of being a human in a pony world."
Brad got in Doctor Downway's face, "We have to try. You did this to him. You can't be so cold as to leave him as an animal."
"I would not have transformed anyone except volunteers. I didn't do this to him. I'm just trying to make the best out of what happened."
Mark got in between Brad and Doctor Downway, "Calm down, buddy. Doctor Downway is right. Although I want to be human again, I'm not sure it's worth the risk. Being an animal isn't so bad. Most of the frustration I've been feeling has been from trying to be a human in the body of a pony. I think maybe I should just try being a pony for a while, just to see if it's okay. Then if it's not okay, I'll try being transformed back into a human."
"Are you sure? We won't be able to have barbecues anymore or go camping."
"We might still be able to. We just have to make adjustments. Come help me get these clothes off. I've had it with them."
Brad's mouth gaped a moment. "You want me to strip you?"
"Someone has to dress and undress me anyway. It defeats the whole purpose of clothing when I have to either have my ass exposed or ask someone to remove my clothes before I can poop."
Brad moved slowly. He unfastened Mark's clothes and slowly slid them off. Mark stepped out of them and Brad stared at Mark's long penis. Mark looked at Brad until Brad turned away and blushed.
"Yes, I have a horse cock now. Your dad owns a horse ranch. Haven't you seen horse cocks before?"
"Yes, but those were just horses. You're my friend. I shouldn't be looking at your privates?"
"No, you shouldn't be staring but I guess they aren't privates anymore. I guess I'll have to get used to not caring if people see."
Doctor Downway spoke up, "You are fairly big down there. Every time you relax, it's going to hang out and show off."
"Is there anything I can do about it?"
"Either you never relax or you tie it up."
"I can't tie it up. Brad, would you mind tying my penis up."
Brad turned beat red. What followed was amazing awkwardness and embarrassment for both Mark and Brad. It was so painfully awkward that you don't want to read it.
After they recovered, Mark said, "I might as well find out what it's like to be saddled and ridden."