Sirius Canis Major persuaded Shatter to age play with him and she agreed. The two dressed like foals, diapered and all and acted more carefree. Of course, they were still themselves so they weren't fully acting like foals. They spent very much several hours doing this and Shatter found it rather relaxing since she didn't have to worry about responsibilities for the time being. Well, she was having fun until she started to feel that all too familiar sensation in her lower abdomen and tail hole. At first she tried to ignore it but than it got so bad that she couldn't forget about it. She stops what's she's doing and flies toward Sirius, landing on her front hooves and knees, but quickly placing one of her front hooves on her abdomen. Even Shatter didn't mind using diapers from time to time, she was not used to doing it in front of other ponies and was considering briefly stopping her age play to use the toilet like a big filly, so she speaks with Sirius about it. It turns out, Sirius doesn't mind and that every time he age plays as a foal, he uses them. Shatter hesitates about her decision but than feels like Sirius is very trustworthy and decides to mess her diaper like a foal even though she's weirded out by it.

Here's their conversation (I know the words are readable but I wanted to put it down so whose answering who since it's not in order it seems like);

Shatter: I know I agreed to do foal age play with you but I got a big problem. I think Nature is calling me! What do I do?

Sirius Canis Major: just do it, it's apart of being a foal. I know it seems weird since soiling diapers is your kink, I don't mind. We're doing a fetish already.

Shatter: I don't know, you sure I should just do it?

Sirius Canis Major: Yes. I do it all the time when I age play as a foal.

Second Part; https://www.furaffinity.net/view/33820730/

Disclaimer: MLP and Transformers belongs to Hasbro. Sirius Canis Major belongs to Me.