By the time they actually step into the medbay, Daine's had more than enough of their collective whining and squabbling. Her own tiredness doesn't really help matters, of course, but the result is this: by the time he calls himself a 'space-runt,' she's cranky enough to flatten her ears and give him a proper snarl. She knows he can't hear her frustrated, Enough!, but her body language is probably conveying as much.

At least his merging has one bonus: because he's injured, it wouldn't be sporting of her to knock him down and roll him onto his back like a misbehaving cub. Even despite his injuries, she's awfully tempted.