Can I Make a Step-Dad into a Biological Dad?

[Violet_Ghost13]

When I first got the game my female sim had 4 children, since then I deleted the father and had her marry another man and have more kids. The new dad was recognised as their stepdad on the family tree and it was all good until recently I aged up one of the stepdaughters. Now there are options for him to flirt and have a relationship with her which I find really weird and creepy. Previously the dad has cheated on the mum when I was playing with another family and I would really hate for him to cheat again with the stepdaughter he raised. Basically, what I want to know is is there any way to make the stepdad into the biological dad of those 4 children? Or at least a way to stop him from being able to have a relationship with them? It's putting me off playing the game tbh so any suggestion is gladly welcomed.

[jpkarlsen]

Just like in real life there are no way a Step-dad could become the biological dad.

Don't do any romantic actions between them and you will be fine.