His eyebrows raise at Diabhall's own theory - he highly doubts it's actually that, but he won't say anything about his own for now -, and then he remembers that such a thing is a serious matter to think about and that he should probably have a more considerate and thoughtful expression about this. He tries to make a smooth transition into a pensive nod, but if Diabhall knows him well enough then he will probably recognize the performative nature of it.

"We can try looking into that too - I'm not sure how the magic works exactly for healing here and if there's any way that they can identify physiological anomalies, but it's worth asking to be sure," he says, sort of an appeasement to show that he's listening to the other man's concerns wholly. As he speaks, he sinks down into the bath and leans his head back just enough to make sure that his hair is all wet for washing. Then, he rises back up from the water and begins the careful process of getting it all clean. It keeps his focus mostly on the task at hand, meaning that Diabhall can steal as many looks as he likes without Allumin being acutely aware that he's being watched.

"What will you do if it's something else?" An attempt to pinpoint how, if at all, to propose his own thoughts on the matter at hand.