Partnered Sims turn into siblings

did you manage to resolve this issue because i've been doing a generation game and my matriarchs (with no prior relationships) keep refusing to woohoo because they have the sister trait despite them not being sisters. 

This has happened to me too, but on PC! No matter what I do it always becomes an issue all over again. My sim's wife will become her sister and then they can no longer have romance interactions. I've seen mixed reports on the issue, ranging from those who think it's base game related to mod related... Personally, it's been a problem for me ever since I accidentally made them sisters through MCCC by clicking the wrong relationship bit. I've tried fixing it through cheating the relationship bits, deleting the sim and adding her back from the gallery, clearing her relationships and starting over on everything, and even trying to use cas.fulleditmode. None of this works, it always reverts again. It's on my one and only legacy save and I've read that others have the issue come back either when they go into CAS or after their sim sleeps through the night. :( This is a really bad game breaking bug, and removing MCCC doesn't help fix it either. 

My game also does this. My sims spouse becomes her sibling. I've tried taking all my mods out and repairing the game and nothing worked.

I just had this come up in my game (PC) *Seems to have happened after I entered CAS when their science baby twins aged up to toddlers. 

First generation Sim I created in CAS, married a townie. 

I am having other issues as well, romantic relationship bar between married Sims going to zero very fast. Trash everywhere it looks like the trash overload event but without the event (no Sims are slobs, no lot traits/challenges, multiple trash bins and a dumpster on the lot) I see Sims empty the trash bin but it builds up so fast.

This literally happened to me this morning. I played on PC and my legacy sim’s romantic partners are now their sister and brother. The only mod i have is MCCC. I’m shocked that there’s no fix for this, as when I looked it up, people haven’t been able to find a fix for over 10 years now.

Same problem here too, and I'm on Xbox so no mods to cause this.  Pregnant looking children, sibling spouses, friggin stop! As someone who is a victim of molestation I can't with this BS. This is game breaking and PTSD activating EA. About to go sink my money on Inzoi on my PC instead🤷🏼‍♀️

Same issue happened to me too. I played on mac and pc.

I have an old save file from about two years ago, where a Sim I created and an NPC Sim got married and adopted a girl. Recently, I started playing with this family again. When both Sims developed the "Fear of Being Cheated On," I noticed that there were no romantic interactions available between them. Then, I discovered something even stranger in the family tree: they were not only spouses but also siblings. Since when?? How did I not know this??

I tried all the methods I could find online: cas.fulleditmode, MCCC, adding parents to both of them separately and then deleting all four parents. Unfortunately, none of these worked. I also know there’s another way to fix this—by uploading one Sim from the household to the gallery and then adding them back to the family. However, this would mean losing all their relationships with other Sims and rendering all milestones meaningless. That’s not what I want. I’ve played this family for over 300 hours, and I don’t want to start over with a new household.

This is happening to me too! It happened in both of my most recent play throughs of Cottage Living. I have no mods and haven't for a while. It happened in the first play through, so I tried a second play through and it literally just happened again. I turned the game off for like, 3 hours and came back and my wives were sisters! I hate this so much

I've been playing in a generation household for years, and for some reason my sims keep getting marked as related??

I have MC Command Center, so I went in and manually removed the "brothers" relationship bit from both sims (even removed the "family dynamic" just in case that was causing issues) and added back the "partner" relationship bit. Their romance bar showed up again, as well as a "romantic satisfaction" popup from lovestruck, but the romantic interactions are still restricted to "offer massage" and "make a move."

Going into their simology, I can see that the game thinks they share the same mother for some reason (even after messing with the relationship bits). Sim A has the correct mother assigned, but Sim B does not. I have tried to reassign Sim B's mother, but the simology doesn't update. 

I've tried looking for the mother in the unplayed households, but I can't find her. She became a ghost before Life and Death (not sure if that's relevant or not) and she doesn't even show up in the list of sims that either sim knows. When I try to add a relationship with "sim in world" she still doesn't show up on that list either. I don't have a headstone for her since all the data for my household headstones got wiped when I installed Life and Death and stored them in a crypt. (I tried going back to old versions of the lot saved to the gallery, but those are wiped as well.

I have no idea how to find this "mother" sim and edit her or at the very least delete her, it seems like it's so deep in the meta data for the game that trying to fix this is out of my depth, please help!

Ok, this is ridiculous. I'm doing a generations challenge and my current couple can't be romantic in any way (and it is causing issues). EA, please fix this ridiculous problem. I tried cheating it in CAS and that won't work. I don't use mods. 

This has happened to me in two separate saves, playing on Mac. In both cases they are a same sex couple. In the first instance I edited them to have the same surname in CAS which possibly triggered it. I made no such adjustment in the second save, I use rotational play so I just came back into that family and found they could no longer romance outside of offering massage. 

Any permanent fixes? I have tried everything and it works, and then almost immediately adds the brother label again. 

This is happening to me too!! Also on separate occasions, I’ve been my legacy for 10+ generations and don’t want loose all my progress because of this bug… is there any solution yet??? I’ve tried using MCCC to fix it but it always goes back whenever I change lots. 

I had to move both partners out (so there is room in the household. 
delete partners relationship (using MCC) Enter CAS and create two random elders. It was letting me connect only one of the two to partner 1, so I left CAS and used MCC to assign the other parent to partner 1.

Delete relationships for partners again. Also may need to delete relationship from partner 2 and partner 1s parents you just made. Go back in CAS and do the same thing with partner 2 and assigning to random parents to them. 

Basically, you need to create 2 parents for each partner and will likely need to keep deleting relationships whenever anything is adjusted to ensure the sibling thing doesn’t come back. After I had to parents for each, it finally fixed itself. 

In then reintroduced them. After that, I cheated their friendship and romantic relationships back to max

I sadly cannot use mods as I play on ps4. I really really do not want to delete a sim qnd have them readied because it'll mess up the relationships in multi families...if this is a glitch then EA needs to fix this asap because this is ruining my families that have science babies, as I'm currently only seeing this happening with family that has science babies 

Currently playing my game right now and I'm having the same issue and I've noticed that the bug only happens when I go into cas , be it through cheats, a mirror, a dresser or even through manage worlds. The moment go into cas, the game immediately turns my sims into brothers

This has been an issue for me dating back over 3 years. Why is this something not being talked about enough? This is a huge immersion breaking issue. I haven’t played with my sims for years because of this issue. It’s been so hard to enjoy the game because I’m not attached to no other families. This needs to be addressed asap.

This just happened to me for the first time! I have never played with any mods or CC - just the base game and EP's. It was my fairy couple and so at first I thought it was maybe something that happened due to fairy influence or something but obviously can see now it's been happening for awhile. Is there a cheat or something that can fix this? I've seen a few people mention some things but that the sibling relationship keeps returning. This is very bizarre and frustrating. 

I have that problem too and it's annoying. Why they can't fix that??? My whole family gameplay is destroyed. They get money for making the game work but they don't get anything fixed. I don't want to play incest families..

I have the same problem. It is only linked to one sim. If I open CAS in ANY mode (i.e., with or without the cheat cas.fulleditmode on) while this sim is in the household, I will exit CAS to have my two married sims thinking they are sisters, and the only romance option is "offer massage". This even happens if I move the offending sim into another household - if I open any CAS with her in the household, even when her spouse isn't in that household, she will think her spouse is also her sister and refuse to be romantic with her, though she still has her listed as her spouse. I've never come across this issue before, it's so sad I cannot edit this sim! 
I have MCCC and UI cheats as my only mods, but from the sound of other peoples' comments this doesn't appear to be a mod issue, as it affects console players as well. 

This has happened to me twice in the same save, its ruining my gameplay.

This just happened to me, my sims are married with two children and are now coming up as uncle and niece , not even with ui cheats could I get rid of this. I had to upload the wife to my library, delete her in game and then add her back through the library :/

Did you fix it? I have the exact same problem 

Just encountered this bug for the first time on PC. There has to be a fix. This is save breaking. 😭 I have a lesbian couple with four children who are now considered sisters. I want my game back, please. Restarting or killing someone off are the only actual "solutions" I have seen anywhere and I dont consider those real options. 

This started happening to me too with the second-to-newest update, and I literally just cannot play my save because my married sims are now sisters!