In Sweet Magnolias, Isaiah's dad is a bit of a mystery. He is never seen or mentioned by name, but we do know that he was an abusive husband to Isaiah's mom. He would often beat her and terrorize the family, which led to them eventually leaving him and moving to Serenity. It's clear that Isaiah has some unresolved issues with his father, and while he doesn't talk about him much, it's clear that he still holds a lot of anger and resentment towards him.