Bucky looks up at her, tilts his head and smirks just a little. What a ridiculous fucking situation, but at least she's making the best of it until the door lets them out.

"Well, I've got a lot more meat on me, so for the sake of survival, you're going to have to eat me, your highness."

It's only logical. He'll keep her alive longer than she'd keep him alive, but even if they were the same size, he'd probably still be chivalrous.

He adds a little bow at the end.