Non-Blooded "Family" or extended (general) relationships mod?

I know between MCCC and a few other mods you can add more extended biological relationships, but I'm looking for something like...a mod where sims can have a "brother of another mother (not literally)" kind of friendship and they are placed in "the famzone." Kind of like how adults can "adopt" non-blooded toddlers/kids/teens as family members in a sense.

Besides the general "don't want the parent/sibling-in-law flirting with the spouse" need, I'd also like friendships that essentially serve as family roles and sims won't hit on each other. But I don't want them actually related. Any help would be greatly appreciate, thanks!