Thanks for the files, that did help. I discovered the cause, when it is doing the incest check the options were if X > # all the way down to the Else instead of Elif. As the Else was the worst option, that meant it always was either triggering some stress or a lot of stress for any incest (even if it succeeded an earlier check).
All that to say, it’s fixed and thanks for the save game to help identify it!