Overlapping Family Trees...

It doesn't take long for sims to not be recognized by the game as blood relatives. I usually have partners picked for my sims by the time they are children and if there are no suitable candidates in town I will find a family with acceptable genetics and use MC to have them adopt a child then transfer the genetics of the parent I like to that child. This way my sim is able to be childhood friends with the adopted child before they are old enough for a relationship.

I personally don't mind overlapping family trees and, like the game, once a sim is no longer recognized as blood, I consider them fair game. I imagine it would take a population larger than the game could manage to not have any overlap and even more distressing to me than sims marrying second cousins is the thought that the only other available sims would be game-generated pudding NPCs :scream:
Here's my current family tree and I have circled the overlaps. Since I started with a small population I knew this would happen before too long.
https://farm1.staticflickr.com/953/40828550085_048d83b4f2_o.png
https://farm1.staticflickr.com/980/39920011250_a1eff4faf6_o.png

@Minx - The sims are First Cousins Once Removed (FCORs) which, like Second Cousins, are not seen by the game as close blood relations. The only way to impose a block on romantic feelings and activity is to use a mod such as NRaas SP and forbid flirts and romance between the particular sims occupying such family positions one pair at a time.

If you find that there are too many such combinations of sims to block each of them that way, especially once we start talking about Seconds, Seconds Once Removed, and Thirds, you could take the other approach with SP and only allow flirts and romance between sims in specified castes. Could be a lot of overhead to work through though.

Without mods, the options for such levels of player control are much more limited.

Honestly, I think these sims might need to travel to other worlds to see what/who else is out there for dating material. :)

@igazor I was hoping Nraas had something that could stop it from happening. I've very limited exp. in setting up castes, but I'd be willing to give it a try. I was hoping there was a "no romantic interaction with any sim on your family tree" option. LOL

@Mikezumi Thanks for the info.

For now I just located a sim in town that was single and got them together. There were other sims available... So, tsk on them.