And there's plenty more in nearly all of the videos.
I don't see anything specifically horrible in the videos. After all, the kids were not abused, and CW could have refused to participate in the game.
The only thing that comes to my mind is that for SW, everything was about appearances. And it is not because she needed to promote her Thrive - rather, she became such a good seller because she could put on a good show.
I think that initially, CW was besotted with her. She was the talkative one, the emotional one, the social one. But maybe at a certain moment, he got tired of all this noisy show? Especially since he (as I suspect) had some problem with expressive speech. So he started drifting away, into the relationships where he was more in control, and also, maybe, ughm... less public? (Obviously less public since he kept them a secret).
Now, all that I wrote is in no way victim-blaming. Simply, these two people were very different and probably not a good match. A divorce is always an option, anything but this horror...and I hope the judges will be just, because he killed three people and an unborn child. SW does not come across as mean, not at all, and she probably was naive if she trusted CW, she was merely slightly too extraverted with her social media.