"Next time, it'll heal in five minutes." Clearly there will be a next time and it doesn't bother him much that she hit him. In fact, he's kind of proud of her as well. She's got a nice punch and ought to hurt anyone human that comes at her.
He does as she instructs, feeling a bit ridiculous but knowing it's the best option then stands as she starts out the door. He's even more proud of her for thinking to take the trash with her.