[Byleth looked up from the book he had his nose buried into (where its cover looked suspiciously like a bodice ripper, with a rather hunky man swooning into the arms of a woman that looked like a swashbuckling pirate) and gave Celine a nod of greeting.]

Hello. Thank you for coming.

[He dogeared the page he was on and set the book down, pushing himself up from his comfortable recline against his travel pack into a more formal sitting position.]

Please, sit. I've prepared a small campfire to boil the water, but... I felt you would rather brew the tea yourself.

[Since Byleth just makes. leaf soup. when attempting it himself (still tastes good, though).]