My parents have been married for more than a couple of decade but my father has been living with his mistress for almost a decade. He now only visits for around 3x a week for a few hours each. He did gave us some monthly allowance once but has since then stopped for 5 years. He never paid our tuition (nursery to postgraduate) and we were mostly raised by our brave dearest dependable mother. We noted that father came to visit more frequently and tried to "care" more (but not monetary wise - we never get a single cent from him!) when I started to become a high-paying professional. My mother's net worth is bigger compared to my father (lets just say he is a business flop, though he spends all his savings on his mistress and their children). Our properties, savings, and car are named under my mom.
My question is that in-case my mother passes away before him (heaven forbid!), what will happen to our house and my mother's assets? Is there a way to make sure that only us children and my mother's siblings get the inheritance? Or is it required by law that my father gets half of it with his mistress and their family?
Thank you very much for your time.