Version Number (you can check on the title screen):
1.4.4.592
Bug Description: Direct siblings can fall in love. This also seemingly eliminates the sibling trait in the mating tent, although I am unsure if that actually works as I do not want to cross that boundary, but it appears as a 100% chance.
What did you do to make the bug appear? I played for a while, currently on a day 182 save and it happened naturally.
Are you able to reproduce the bug? If so, how?: Unsure if there is a direct method to reproduce it but it happened randomly.