Ianchus sees that stiffening, and he leans back a little, as if to express that he's aborted that particular movement. He's incredibly physical, of course, but he'd never begrudge someone for their personal space. Only utter cads do that.

But he can't help but smile kindly at the words, the way Carlisle says it.
"What are you talking about? You've been an utter darling." Perhaps there's a bit of teasing there, but it's sincere, as well.

True, Carlisle is prickly. But he'd never begrudge him for that, either. And he's never been cruel, and that's what, to Ianchus, is most important.