The thing is is that both characters still see each other as family in and out of these routes. It's also the fact that all the characters realize that it'll reflect on the both of them so badly that it would cause an uproar from the public if it got out, hence their need to hide after all has been said and done. The MC even says that, blood or not that is still her brother so it's just,,, eugh. Doesn't help with the fact that because people don't think that step family/foster family still count as family, they can do anything or whatever (which, irl has led to real bad things, of which is why I say this could be really uncomfortable for people, me almost being a victim of this sort of thing for example) so it's just,,, so bad. so so bad