Separating/ Divorcing your Sims - TS4

The very first time I had sims divorce, was due to the fact that the dad had the insane trait. The couple had adopted a child, I made up that the father had mental health issues in his family that were genetic, hence the adoption. Since I play rotationally, whenever I was playing another household, the dad would be dirty and sleeping in the park, so I had the mother divorce him on the grounds his mental health was getting worse, and she was no longer able to deal with it and raise their daughter.

Eventually, I edited him so he no longer had the insane trait, both eventually remarried, happily, and had more children, so it all turned out well in the end. The adopted daughter grew up quite lovely and married an immigrant who was kind of funny looking, but had all good traits.