Propinquity.

it often amazed her how similar they behave, n how much they represent each other, truly like father like son. yet neither of them was consciously aware of it. disliking each other, badmouthing n backstabbing were a common occurrence within the household. perhaps not all birds of the same feather flock together. seeing this so often was enough to have her jaw dropped. but despite the frequent aggression, their relationship can actually be labeled beautiful in they eye of an observer if one knew them well enough.

大まかな関係。