Good plot why do they have to be half -brothers?

What?? They are not even biologically related at all beside as an in-laws

I'm glad been fed up with the step-sibling trope or half-siblings might have overrated (▰˘◡˘▰)

No! They're not it's only cause he it's suppossed married with the long death related by Blood sister but she died.

I heard darling