His mouth presses in a little, hiding the way his lips want to curl up in a tiny smile. He knows very well that Wangji is being petty, and he shouldn't smile fondly at it when his brother has successfully dismissed the argument without conceding any points. But he is fond, exceedingly so.

And he doesn't want his brother to be unhappy. "Next time, I will stay by your side."

There will always be a next time, and he can't promise the times after that, but he can agree to stay close to Wangji the next time they find themselves in a dangerous situation.

He takes the newly named rabbit back, cradling him gently against his chest, and just as carefully changes the subject.

"Wuxian has offered to come with me again, if they return as they said they would." Which Wangji may already know, but he doesn't bring it up just to inform him of it. Wuxian had brushed off Lan Xichen's concerns about the danger. Wangji will not.

"His own safety does not often seem to factor much into his plans." It isn't a criticism. It's worry.