You smile as you enter in the little hole of the jam doughnut and even decide to steal a bit of it for yourself, the sweet flavor increasing your excitement a bit.
From your position you couldn't see a thing of what was going outside, only hear the muffled rumble of the gigantic ponies as they celebrated whatever they were celebrating. But you come to realize it's more fun this way, instead of picking a particular target to explore their body, they get to choose you instead. Who will eat this doughnut first, which body are you going to explore first?
You keep having a little party of your own stealing some more of the sweety filling of the doughnut and patiently waiting for your turn, which allows you to both experience what it feels to be food, not very interesting in itself but somehow with a purpose on it as you look forward to be eaten, and also plan what you wanted to do once you entered into one of the ponies. You were entering via their mouth obviously so should you go up and explore the rest of their heads? Or maybe should you go with the food directly to the stomach? Your curiosity was about to be satisfied, and you note you don't have any particular preference over where to go, just on the fact that you want to explore their whole bodies if possible.
Time goes by and you keep asking yourself more questions, one of them being who would you actually want to eat you first. It's not like you are close friends with any of them, but they were well known enough for you to recognize them. You thought Twilight Sparkle, Princess Celestia's protege, would be quite an unique pony to explore, something that both encourages you and discourages you a bit at the same time, feeling that if whatever was inside her was endemic to her only it wouldn't be so fun.
Losing a bit of patience you leave your hideout and go up to see how the mares are all chatting with each other and having a good time, making you shake your head and ditch your previous thought. Sure, the purple unicorn was unique, but all her friends also had unique things about them, those marks, some curious personality traits and surely inside their bodies they would all be different too. In the end you couldn't decide either, you just resign yourself to be patient and explore one at a time because you haven't mastered the art of creating clones of yourself yet.
You go back to your hiding place and wonder about something else, what would you expect to find inside them? Your fantasy was being inside a pony, but was it merely getting inside of finding something nobody else has found like the source of their magic or what makes the ponies different among each other? You were still thinking about that when finally you feel the doughnut surrounding you moving. Looks like somepony is about to eat you
What happens next?