I don't know but I'm still trying to figure that out myself. :D
I do have my suspicions despite not always having concrete evidence.
So before all this took place, this happened which shows Jean, the daughter-in-law leaving after being shooed by Kibwe. I suspected that she was trying to announce a proposition to him which was denied before anything was ever spoken. Probably because this wasn't the first time she tried. In fact, I have observed her making many advances towards him over time. However, I think Fatima's suspicions weren't factual at this point and she overreacted instead of just having a conversation...communication with her husband about the matter. Sure, people and highly likely Sims can lie but at least that can be a part of the repertoire for problem-solving especially if done honestly. But who knows, maybe Kibwe put a stop to being exposed like that. Sims can be quite secretive actually and I sometimes just catch clues and hints here and there when something is amiss.
https://i.postimg.cc/G9nwrwsD/Screenshot-298.jpg
Exhibit A (I observed this and watched it all play out when I switched households as I wondered what they were up to.)
The wife, Fatima, apparently invited Yoshi over who recently had aged into a young adult. She is gossiping about something though it may be that she knows of her daughter-in-law's flirtatious nature towards her husband and possibly suspects something is going on between them. The husband, Kibwe, came home from work and he didn't hesitate to go straight for Fatima probably sensing something was off about this situation.
https://i.postimg.cc/KYnQy8W5/Screenshot-304.jpg
https://i.postimg.cc/VNRGCNFk/Screenshot-306.jpg
https://i.postimg.cc/C5ZmXspR/Screenshot-310.jpg
https://i.postimg.cc/FFqPc803/Screenshot-311.jpg
https://i.postimg.cc/Cxpmr8PK/Screenshot-312.jpg
https://i.postimg.cc/pLQkwd4J/Screenshot-314.jpg
https://i.postimg.cc/TPC0P4Ry/Screenshot-315.jpg
https://i.postimg.cc/cHCmtBHF/Screenshot-319.jpg
https://i.postimg.cc/HxNtw88d/Screenshot-321.jpg
One of the sons, Kanyin, autonomously found Yoshi at the winter festival and started to berate his ignorance. To me it seemed he heard or found out about whatever was going on with his mother and Yoshi and wanted to discourage him from proceeding with whatever was going on between them.
https://i.postimg.cc/43brv9cD/Screenshot-357.jpg
https://i.postimg.cc/76ttXMZW/Screenshot-358.jpg
https://i.postimg.cc/Ssg33bDV/Screenshot-359.jpg
https://i.postimg.cc/1XTTRcxq/Screenshot-360.jpg
https://i.postimg.cc/wxbnkHtj/Screenshot-361.jpg
https://i.postimg.cc/c4pjVmBq/Screenshot-362.jpg
https://i.postimg.cc/vmzNxdFM/Screenshot-363.jpg
Since then Kanyin had been distant from his mother but I directed her to apologize and had them talk. Don't know if that really did anything though.
https://i.postimg.cc/vmk3V8qJ/Screenshot-392.jpg
https://i.postimg.cc/FRSGgtw7/Screenshot-393.jpg
https://i.postimg.cc/J0Wxp6WK/Screenshot-396.jpg
https://i.postimg.cc/prYZ4fWv/Screenshot-397.jpg
Now I don't know if Kibwe sometime after these events did end up cheating and if so not sure with who. I noticed that one of the grandsons, Zaire, became upset because of something he seen his grandfather doing. The odd thing is, I searched and searched this lot and could not find Kibwe at all to find out what was he doing and with who. It wasn't until after the lot had closed that I finally saw him leaving yet still could not figure out where he came from and I think I came to the conclusion that he was there but for some reason invisible to me. Like if it were some kind of different rabbithole in plain sight or something. But honestly I could have just overlooked but I'm for sure I looked in the area where I saw him going down the stairs and it was only him. I didn't see anyone else and I stayed behind for a few real life minutes. I'm still confused about that. :D
https://i.postimg.cc/hPK1Z4vq/Screenshot-490.jpg
Then later I had Kibwe become one of the professors to teach a University Prep Course for setting up future students with scholarships. He flirted with most, if not all, his female students which made matters for his marriage worse. I don't know why they continue to let things slide. I guess because they both have a large family and both are family-orientated and they don't seem to choose divorce. Though honestly as much as I do like them as a couple...what's the point? The kids will eventually get over it and hopefully be happier for it because I think it is way more damaging to stay together than if they go their separate ways. One kid is already showing signs of depression and detachment.
https://i.postimg.cc/VkbKRy8s/Screenshot-1022.jpg
This surprised me when I was playing his oldest son household and Kibwe visited. He played video games with the kids but then went upstairs alone with his daughter-in-law....
https://i.postimg.cc/jSHbq5YV/Screenshot-1259.jpg
https://i.postimg.cc/D00v05y8/Screenshot-1269.jpg
https://i.postimg.cc/v84DYWPp/Screenshot-1273.jpg
https://i.postimg.cc/7hzxgndh/Screenshot-1274.jpg
https://i.postimg.cc/ncvFrTqw/Screenshot-1276.jpg
I even had Fatima flirt and cheat on purpose in public to see if word would get back to Kibwe and whether if he would divorce her or not. So apparently, the son-in-law, Myles is just going to ignore that, that even happened...right. He's so mad at his twin brother though. :D
https://i.postimg.cc/prHBb2zB/Screenshot-1447.jpg
https://i.postimg.cc/VNtMYxYZ/Screenshot-1458.jpg
https://i.postimg.cc/5yKj5g4F/Screenshot-1460.jpg
https://i.postimg.cc/2Sr8qgFX/Screenshot-1462.jpg
Does Myles just not care? He didn't tell Kibwe what he saw but will he tell Fatima what he saw though a lesser offense. This though was autonomous and I just watched. On another note, Myles surprised me and cheated on his wife so how is he going act like that. :D I'm about to break up all my cheating Sims eventually.
https://i.postimg.cc/4yYHSqF1/Screenshot-1482.jpg
https://i.postimg.cc/26LJG87j/Screenshot-1484.jpg
Booing, right. Well I know for sure this time that Fatima cheated and this was her husband's and others reactions. She is pregnant with her husbands child and it's not the last time she cheated while pregnant.
https://i.postimg.cc/3x2fVw0K/Screenshot-695.jpg
https://i.postimg.cc/FzBFMZqJ/Screenshot-696.jpg
https://i.postimg.cc/0yq1bFpy/Screenshot-702.jpg
https://i.postimg.cc/RV1XTZ3K/Screenshot-703.jpg