Emily looked at you with delight as she said, almost uninterpretebly, "Dwess Up!" You barely understood what she said, and she grabbed you and made her way over to the small closet her mother allowed her to have so she could have a place for all her dolls' clothes, since she honestly could care less about the actual dolls themselves. The reason behind this was she had overheard her mother talking about getting her an Elf four months ago, and knew she'd get bored if she didn't have something to dress the living dolly up in.
As Emily sat you down, she looked at you and said something, again, uninterpretable. She repeated her words, saying them slower than before and you could make out, "...Dwess up...you choose...outfit..." Understanding just the right words, she pointed into the closet as she closed the door behind you both, before making a crooked face. Hearing a gurgling little fart, you realized that Emily was about to poop in her diaper. Apparently, that's not the only thing she had in mind of pooping into her diaper, because she took off your current pajamas, leaving you naked on the ground, and picked you up as she spread her legs and arms to be out on all fours. As she did this, she took hold of one of the many dolls' clothing-filled boxes and put the hand she picked you up in into her diaper before sticking her butt out into the air, causing her rectum to expand just enough for her to easily slide you into it. She giggled as she felt you try and get out before she wanted you to, making her poke her pink-diapered behind as high into the air as she could stick it. Doing this, she stuck a finger and probed around inside her anus, making the rectum bloat out so much you could jump up and down. You had no clue why she was doing this, but after she sat down and the bloating traveled up deeper inside her, you realized she wanted to get as many loud farts as she could out of this. She repeated the process she had done before several times before she noticed that her tummy was sticking out noticeably farther than it should be.
Deciding that she had enough loud farts inside her, she lowered her butt down slowly, as experimenting with this before she knew if she did it too fast all the farts would come out at once, followed by you and the huge mess that lay deep inside of her. Finally lowering herself down to the floor, she found a plastic doll she asked her mom to buy for her months before, it being one that looked almost exactly like you did, besides the clearly plastic body. But far away, it looked just like you. She slipped the pajamas onto the fake you and opened the closet door. She headed over to the dollhouse you had seen but not been taken to yet, and slid the plastic doll under one of the bed's covers, tightly packing it in and kissing it on the forehead, just as her mother walked in.
"Playing Dolly with your little friend already, are you?" you heard your master say to Emily as she giggled and squirmed in place a little after turning back to face her mother. "What's the matter honey, you okay?" she asked, and Emily shook her head no as she pointed to her behind and made a soft grunting noise, which you suppose was telling her mom she needed to desperately poop but was unable to at the time. Your master noted this and walked away, carrying her daughter in her hands. You were lying down inside her now, still just behind her anus and, to you, your freedom from this hellhold. To be frank, it was actually kinda comfortable in there, and quite warm too. The warmth was just perfect, you decided, and you were lying down on your back. The warmth was starting to get to you, as you started to get drowsy and hear your master feed Emily some extremely-fast acting laxative formula that was mixed with several other items that would only amplify her messing.
After Emily's mother finished, she put her back down into her room just as...