This bug was fixed in Patch 1.19.31. This should no longer happen to your Sims but it won’t fix already borked Sims. With the patch, a new cheat was added so you can get rid of the wrong ones easily
- Type: testingcheats true
- Shift-click on the Sim and choose Marriage and then clear the faulty one
- My family tree suddenly shows my Sim married to another Sim I don’t know.
- My Sim is already married and now there’s suddenly a second partner in the family tree
- There’s an unknown child in my family tree.
The game has decided that unhoused NPCs that go to a restaurant with a housed NPC need to be married. Hence they are marked as such.
Something similar happens with the children. For some unknown reason it creates children for Sims going to a restaurant together.
The following method can be done without mods, just with cheats. It’s not 100% satisfying though, since some of the icons you see in the relationship information are wrong afterwards. The only way for a satisfactory solution I’ve found so far is using MC Command Center (see below)
- Choose the Sim with the wrong partner and invite them all to a lot.
- Since my Sims both have a relationship outside their marriage, I have to tree divorces
- Clara divorces Tomaso
- Bjorn divorces Krystal
- Clara and Bjorn divorce.
- Everyone cries and is angry at each other.
- The family tree is now completely messed (only ok when looking from the children’s point of view)
- To repair the family tree, Clara and Bjorn need to get married again. This can be done by several means. The easiest is to use the cas.fulleditmode cheat.
- After doing so the family tree should be fixed.
- The relationship itself can be fixed to a certain extend with Cheats.
How to prevent
You can try the following thing to prevent the bug, since the error occurs if you two NPCs go to a restaurant together
- Move as many NPCs as you can into a house and make sure you only have a few unhoused ones.
- Don’t play any legacy games where the relationships of your neighbors and their family trees are important.
- Don’t go tot restaurants until the bug is fixed
- I would not do above fix if you are already infected at the moment. Wait until the bug is fixed and do them all then (at least the ones that are important to you) If you do it now and play again, it will just happen again.