You were walking around when you saw a Miraidon with a bulging stomach, he saw you and grabbed you, easily swallowing you whole. When you landed in his stomach, you landed atop the belly of a Koraidon.

Koraidon: oh~? You caught a little human, huh big bro~?

Miraidon: yup~! He is all yours, little bro~. Feel free to do whatever you want to him~.

Miraidon rubbed his tummy, grinning as he felt both you and Koraidon inside his stomach.