The infant heir to the throne of another planet is torn from his home and family by human magic & thrown into another world. Using telepathy, he asks a pony to take care of him, and she agrees. Born as royalty, he must live a common life.
Bon Bon, anxious after the Bug Bear came to Ponyville, she speaks with Celestia. What she finds out shocks her. Her clone made in case she needed replacing is still alive. Not only that but she lives in Ponyville!