The snap rattles him more than he expects it to, Xichen tenses but does not move away to put great distance between them. If it is meant to push him away, for the moment, it does not. He stays close, sure the answer is that he is not helping but for the moment unable to move.

"I-- I'm sorry. Alright." Simple, a soft word and there's fear in his voice but he does not press now, giving Wanyin a moment to gather himself as he watches him with worry in his eyes.

How much does the other know about this disease, this affliction that is spreading to them both? He wants to press, to know, but not when the other man is still gasping for air. "I only wish to make this right -- To make sure you're alright."