Pinkie Pie made use of the party house since the day I gave it to her. And, one of her first parties, in fact her very first party, in that house was when a little girl she’d made friends with in Primary was going to have a third birthday, and Pinkie wanted to throw a party for her.

The little girl gave the planning of the party to Pinkie Pie, while she made a list of friends and others she’d invite.

Pinkie was really excited to be able to throw a party in the new building we'd made for her for that purpose. She carefully made plans on what events would happen when and where the tables and chairs and other items would be placed. And, one thing the little girl specified was that it was going to be a pony slumber party. The only problem, it turns out, was the little girl didn’t explain what a pony slumber party is, leaving neither Pinkie nor I any idea of what to expect. We made the assumption that it would have something to do with the original My Little Pony cartoon, the one that was being produced at the time, and that the definition would be revealed when the birthday girl arrived with her friends. And, we would learn, on the night of the party, that we would be at least partly right in our assumptions.

In the mean time, Pinkie had planned for dinner to be served first, with spaghetti for the main course, cake and ice cream for dessert, and various kinds of fruit drinks for beverages. She had the tables placed on one side of the main party room so the children could eat there, while the other side of the room was designated for the opening of presents, with the area in between being designated for games. She even decorated the room with streamers, balloons, and other decorations she thought would be appropriate for a birthday party. Everything was ready for when the birthday girl and her guests arrived.

On the day of the party, the birthday girl and the guests she’d invited arrived; and I left Pinkie Pie alone to greet them, although she had a phone to use in case she needed to contact me for any reason.

As I remember, it was about the time that I started preparing food for the rest of the family that I got a phone call from Pinkie Pie.

As soon as I answered, I heard the pink earth pony whisper, “D-daddy, I think I’m in t-trouble.”

I asked, “Pinkie, what’s wrong?”

Pinkie answered, “I j-just found out wh-what a p-pony slumber p-party is.”

I began to get concerned for the pink earth pony when I asked, “And?”

As I remember, Pinkie started crying when she continued, “D-d-daddy, th-th-they’re t-t-taking their c-c-clothes o-o-off.”

I admit I couldn’t hide my confusion when I asked, “Huh?”

Pinkie continued, “She said that for tonight they wanted to be like me. I don’t wear clothes, so they decided they didn’t want to wear clothes either.” After sobbing once, Pinkie continued, “Daddy, I’m scared. What if one of them wets herself, or messes herself, or worse? What’ll I do?”

I paused for a moment before answering, “The party house is yours, Pinkie. And, being your house, whatever rules you make for it are for you to enforce. And, if they want to be a pony like you for the night, then you have to set the example. If you’re afraid of them urinating or defecating on the floor, then give them a tour of your party house with emphasis on the bathrooms. You wanted all of them on opposite sides of the party room, remember? Ten for mares and ten for stallions? And, since this is a group of little girls, you can take them into one of the bathrooms for mares, and even demonstrate how you use the toilet. Let them know that when they need to urinate or defecate, they should go to one of those rooms and use the toilet there.”

After hearing my advice, Pinkie Pie swallowed hard, or at least noisily, then sighed, then said, “Alright, Daddy. I hope this works.” And, she hung up. And, I didn’t hear anymore about it until the next morning.

In the mean time, naturally, a recent friend and I were worried about her. But, like I’d said to her, the party house was her territory, for all intents and purposes, and it was up to her to make and enforce the rules for it. And, I had to at least demonstrate confidence that Pinkie Pie would know to do the right thing in this situation.

And, so it was when we had dinner there in the kitchen, and I dismissed my friend before heading to bed.

In the morning, I heard the front door slam open, the sound of galloping from there to Pinkie’s bedroom, then her door open and slam closed again. I’d expected to get a report on how the party went, and, based on her heading straight to her room, my guess was things didn’t go well. Still, I was surprised that Pinkie went straight to her room instead of coming to me first. So, I headed to the pink party pony’s room to get the report from her.

When I got to her door, I heard her bawling on the other side. Further evidence that things hadn’t gone quite the way Pinkie had planned. I knocked on the door and asked, “Pinkie, is everything alright?” When she didn’t answer after a few seconds, I asked, “May I come in?” I did get a response to that, if nothing more than her stammering about the door. So, taking it as an affirmative response, I opened the door and entered her room, then closed the door behind me. I took a seat on the bed next to her and asked, “So, what happened?”

Pinkie Pie had buried her face in her pillow. And, considering she was crying, I wasn’t surprised when she turned to me, and I saw that her eyes were red and she had tear lines down her cheeks. She answered, “W-well, I d-did what you s-said I should do, a-and I sh-showed them the m-mares’ bathrooms. I even sh-showed them h-how I use one of the t-toilets.”

Encouraging her, I asked, “And, what happened?”

Pinkie looked down and sighed, then looked up at me again and continued, “W-well, I thought they understood. Th-they acted like they did, anyway. W-we, the girls and I, had a lot of fun at the party. Then, when it was time for sleep, well, … there was this one girl who was older than the others. And, she volunteered to watch over the others so I could get some rest. Well, I was tired, so I figured, why not? So, I went into the hallway, just outside the door, and I fell asleep. I figured that, if the girls needed to use one of the mares’ rooms, they’d let me know.” At this point, she put up a short battle with her emotions before turning away from me and burying her face in her pillow again and sobbing.

Well, I reached out with my closest hand and stroked her back and said, “I’m guessing things weren’t as under control or as perfect as you thought they’d be?”

Pinkie continued, “I woke up after a few hours, and the doors hadn’t moved. I-I entered the main party room, … and … I s-s-smelled … I s-s-sme-e-elled …”

I asked, “What, Pinkie? What did you smell?”

Through her sobs, Pinkie continued, “Th-the birthday g-girl h-had gotten a s-stable for one of her p-presents, and … and she and th-the other g-girls had b-built it so they c-could sleep inside. W-well, I d-didn’t like what I was s-smelling from there, s-so, I g-galloped to their s-stable and looked inside, a-and, and I saw … p-pee-pee … and … p-poo-poo … all over in there!” She sobbed again before continuing, “I d-don’t know why th-they didn’t j-just use the m-mares’ rooms l-like I sh-showed them. Th-they just w-went wherever they w-wanted, I g-guess.”

I asked, “Well, you did get it cleaned up, didn’t you?”

Pinkie nodded as she answered, “I w-woke the g-girls up and m-made ‘em … c-clean up th-their their own messes. And, they did. They g-got their p-pee-pee and p-poo-poo cleaned up … and got dressed b-before their parents got there to p-pick them up. Th-the b-birthday girl even t-took her s-stable down and p-put it back in its b-box. B-but, my p-party h-house still smells like a p-potty h-house.”

I stated, “It sounds to me like it just needs to be aired out.”

Pinkie hugged me around my rib cage as she said, “I h-hope that’s all it n-needs.”

At that point, I picked her up and held her and said, “Let’s go and see how things are in there.”

Immediately, Pinkie pushed away from me and said, “N-no. Y-you c-can’t go in th-there.”

I started to stand up as I said, “You said you had the mess cleaned up, and it just smells bad now.”

At this point, Pinkie Pie shook her head before saying, “N-no. Y-you don’t understand. It was my first p-party in my p-party h-house, and it was a d-d-disaster.”

By now, while I was still holding Pinkie in my arms, I was also standing. I said, “I built the party house for you so you could use it more than just once. Whatever mess is still in there I’m sure can be cleaned up. And, if it just needs to be aired out, then that shouldn’t be a problem.”

Pinkie argued, “B-but, I f-failed those g-girls. I thought they understood, and they didn’t. I thought I could trust th-that older g-girl, and I couldn’t.”

I proceeded to carry the pink earth pony out of her room and through the hallway as I said, “This was the first time you used your party house the way it was designed, and it sounds to me like you did a good job with it. You set the rules, and you showed those girls how you use the toilet. Now, maybe their parents haven’t properly trained them yet. I can’t blame you for that. And, as for the older girl, and you being tired, well, maybe she wasn't as trustworthy as you thought she was. If you don't think you can trust her, if you feel like she betrayed your trust, then you shouldn't let her into your party house again. And, if you need our help enforcing the rules you set, then don’t be afraid to ask us. That’s why we’re here.”

Pinkie Pie just kept pleading with me after that not to go into her party house, but I just headed to and out the front door, closing it behind me, then proceeded to and into her party house.

Well, when I took my first step in there, if there was any smell, it was so faint that I couldn’t really detect it. That is, not until I walked into the main party room. And, sure enough, there was that lingering smell of urine and feces. The good news is the stable, likely a play house, the girls had put up and taken down must’ve come with its own floor. Well, I took Pinkie Pie out of the main room and put her down, then opened the doors to the party room and the entrance doorways to her party house so it could air out. And, it took only a few hours before I decided that there wasn’t enough of the smell to require leaving the doors open anymore, and I closed them again.

Suffice it to say this wasn't an isolated incident. And, every precaution Pinkie tried to take didn't seem to make any difference. There were just some children that were determined to either enter unclothed or take their clothes off once they got inside, then relieve themselves wherever and whenever they needed or wanted to. Some rules, like a diaper rule, that Pinkie tried to enforce only ended up with bigger messes being made. And, when Pinkie tried to enforce a "wear clothing" rule, the rule was so vague that children would come in wearing just a shirt or just a sock, just the minimum to say they were wearing something. When Pinkie tried to set the example of what clothing she wanted the children to wear, even that caused the children make up their own ideas of what the pink party pony meant, or the children poking fun at how odd it looked for a horse, even of Pinkie's size, to wear clothes.

An adult presence only helped, it seems, as long as that adult could see what was going to happen and could react quickly enough; as children would gather their friends around them to defend them as they relieved themselves. Some even just messed or wet themselves in their clothes, thinking their clothes would hide or contain the mess, or wouldn't reveal it immediately and/or in conspicuous amounts.

When Pinkie Pie eventually, and sadly, outlawed pony slumber parties, not even that stopped the incidents from happening.

If there was one thing that helped more than anything else, it was when Pinkie Pie earned her wings, and later her horn. The ability to fly meant that she could see the children from above and see if any of them were acting like they were urinating or defecating, or preparing to do so. And, while she was able to cut back on the incidents, she couldn't stop them completely.

Of course, when she got her horn, she used her magic to sense the bladder and bowels of each of the children, and detect when a child would need to urinate or defecate. This use of her magic was uncomfortable and exhausting for her; but, it was the most effective in keeping the children from wetting or messing themselves, whether they were wearing clothes or not. She still didn't allow pony slumber parties, which I figured was all for the best. Also, she needed to be in the room with the children to be most effective.

In some cases, it also helped to have one of my own children, when I had at least one and they he or she was old enough, to demonstrate how they could let Pinkie know when they needed to use the bathroom, usually covering their crotch when they needed to urinate or their behind when they needed to defecate. And, from there, if it was a boy, I or my son (During the time I was caring for Pinkie, I had two sons; but only one of them would grow old enough to help her.) would take him to one of the "stallions'" rooms; or, if it was a girl, then my wife or my daughter would take her to one of the "mares'" rooms.

Still, there was that rare child that refused to leave the party room unless the party was officially over. And, because that child would come in wearing single-piece clothes, such as coveralls, overalls, or a dress, Pinkie was suspicious of such children; and would make sure they were wearing underwear before she would let them in.

Incidents with these children seemed to persist as long as Pinkie Pie ran the party house. After she returned to Equestria, one of her human siblings took over running the party house the way she did, as a business. But, after it was clear that the pink party pony was no longer living with me, the incidents with the children stopped, leading to us wonder if someone in town had something against Pinkie Pie, and was trying to drive her away. And, while there did seem to be one father or mother, while the party pony was here, that insisted, in spite of the evidence against him, that their "perfect son" wouldn't abandon his clothing to urinate and defecate all over the floor, those families disappeared after Pinkie returned to her home, and I haven't heard from them since. And, the rules Pinkie made for her party house were strictly for her party house, and never made into laws outside those walls. But, while they've been modified somewhat, they're still enforced.