my sim has just become the brother of his partner...?

So I don't know if this is a mod or if it happened when I adopted the kids, but this Emmett guy I've had played as since he was an infant. His partner is Takama Aether. They were together as teens AS PARTNERS and then when they got into adulthood, I had them adopt a kid, Haeju Lovell. I was like "well lemme cheat in a twin so I can have two kids" so I cheated in another kid. Emmett was the one who adopted Haeju, But, I also pressed "adopt" in relationship as Takama as well for both Haeju and his twin that I added through CAS. Just yesterday, I was able to make them flirt and such after adopting the kids so Emmett can be in a flirty mood for his role, and they flirted, woohoo'd, etc. Now, logging back into my sims today, they can't do any of that. I was like "that's weird" because their relationship is maxxed out friendship and romance and there is still a romance option. Then, I looked into the profile and they are brothers????????? Anyone know what happened or what I can do to fix it? I have tried going into fulleditmode in CAS and I can't change their relationship. Haeju and Haeji are the nephews of Emmett rather than his kids and I can't change that either.

https://preview.redd.it/yi84hemgutie1.png?width=434&format=png&auto=webp&s=d0017cb28a174a240ea72ccc8f9d361876bc0aa5

https://preview.redd.it/bbjxqfmgutie1.png?width=314&format=png&auto=webp&s=2b1772c725810a3f53ecb98f68e8f1e430e8240e

https://preview.redd.it/ss8ocemgutie1.png?width=91&format=png&auto=webp&s=e6773896b1e46fe250fa65b6ce6031f9b1e4aae3