When Kaveh first came to stay in his home, Alhaitham was much displeased. Not only at the man himself, but also at the fact that in fact his new roommate so happens to have a child. Not that he wanted a kid poor and on the streets, but he was not verg much fond of childern. Especially if that child belonged to Kaveh.
Though, it seems that they didn't get Kaveh's most boastress qualities, thank Kusanali. No, the child much more preferred to hide behind a book and just listen to the environment around them. Unexpected, but Alhaitham didn't necessarily care to judge. He was like that as a kid too.
But to his surprise the child took a liking to him. More so than their father, who honestly didn't take it too well. Whining all the time about how they liked Alhaitham more than him. But for the first time, Alhaitham didn't care. Not that he always did care. But because he found himself liking the kid too.