She's completely absorbed in eating. It's perfect... You slip slowly around and forward, your hands out and fingers flexing as if getting prepared for the action you have in mind. As you approach the door that would lead outside, you have a moment to wish you had been hiding in a bush instead, but maybe she would have seen you, or smelled you, or used some other sense a magical pony might have. In either event, being behind a door seemed like a far safer bet, but it was in the way of your pounce.
You have to make the best of it. You wrench the door open, charging at her in the same motion. Her eyes are already on you when the door opens. Did she hear the door open, or did she notice your approach from before them? Hard to say. She's midway through turning around, but you're coming in fast. You land on her back and wrap your arms around her barrel, grabbing her tight. "Hold it right there." You were going to hold your horse as literally as possible.
She squeals in terror and her little legs kick out, but she can't get a good angle on you as you hold on tight for dear life. A little horn pokes free of her mane, glowing brightly as magic engulfs your form. You barely notice it, far too busy keeping a grip as she bounced around, dragging you away from the door. Your entire life becomes keeping a good grip around her midsection. She's soft, warm, and nice. She's a good pony. You feel you could hold onto her forever and would be happy doing it.
Fortunate, because that was exactly what you'll do. Your senses never return in the same way, as you have become a saddle, strapped tightly to her, always hugging her close and keeping a good grip on her equine form. She runs off with you still attached, free of your attempt to capture her, and yet, she never discards you.
Would you like to try again?