Tina paused as she went over information in her head: Leah just pooped herself. Heavily. She practically had no control at all, meaning she must've either not felt the need to go or ignored it (both very babyish in nature). Despite this positive turn in her behavior (at least in Tina's opinion), it wasn't a normal one. Tina thought that pushing Leah's little toddler game would be something they could both bond over: Leah liked acting like a toddler (or Tina thought she did), and Tina liked taking care of them. However...it's clear that this was going a little further than just a game, and Leah does not looked pleased.
Tina thought pushing her into this silly role would be harmless while she and her new husband go on a vacation, but now feels like she does what she usually does and over did it. She had a number of ways she could deal with this: The plan could stay the same, as Tina's sure Leah wouldn't need extra care outside of more diaper changes, and even then it would be easy enough to teach her change herself. Tina could also implement a potty training course for Leah---she could clearly use it---but her sister wouldn't be down for that (also, she realized, it would probably be incredibly demeaning for Leah wouldn't it?). She could take Leah with her on vacation, and possibly help her course correct (or, alternatively, convince Leah to STAY like this, and maybe even become more baby like? Tina entertained the idea, but quickly squashed it). However, she realized the obvious thing to do was---much to her distress---the last thing Tina would think to ask.
"Rita, do you have somewhere Leah can change?"
"Of course. Right in there."
"Thank you. Follow me, please."
And the two walked into the house towards a little room with a changing table set up in it. Tina gently patted the surface, making Leah groan. She crawled up onto the table and laid flat, looking embarrassed and miserable. Tina gave a steady breath before she began changing her.
"So Leah, as cute as your little display was, it might've put a wrench in our plans." Tina said playfully, though Leah looked less than amused.
"I swear I don't know what happened. Please don't tell me you're going to take me somewhere else?"
Tina hummed thoughtfully, wiping the poop off her butt carefully.
"Well, there's a few options available, but I never really asked you: what do you want?"
Leah looked shocked, as if this question was ALSO the last thing she expected Tina to ask (which does hurt Tina a little bit).
"I don't know. What are the options?" Leah answered a little hesitantly. Tina quickly lays them out, making sure to point out the pros and cons. Leah nods along, still rather upset but seems happy to have a choice now.
"So, what do you think? I must admit, I would love for you to come along with us on vacation."
"If I act like a baby?"
"Aww, don't be like that. It's cute! I'm sure everyone else would love it!"
"Uh huh..."
"...but it's not required, no. I have a feeling you'll be needing diapers for a while, though, if that adorable little accident is anything to go by."
Leah groans in embarrassment, but considers her options carefully while Tina peppers baby powder on her waist. Much to Tina's extreme delight, Leah was sucking her thumb and didn't seem to realize it; she really was turning into a baby! She tried to keep her delight in check, though, as to not make Leah aware.
Finally, Tina tucks a fresh diaper under her, and folds it around her waist.
"There, all fresh and clean! Have you figured out what you want?"
Leah sits up, testing her underwear with a few shakes and nods. She starts to speak before finally noticing the thumb in her mouth, blushing profusely before ripping it out and wiping it off, side eyeing Tina in hopes she didn't notice (Tina did, of course, but she wouldn't allow Leah to know).
"Yeah, I think I'd prefer to..."