The family is concerned because they've noticed a sudden change in their father's behavior. He's started spending money more freely and acting differently since he met a new person. This is particularly concerning because he used to be very careful with his money. They're worried that he might face financial problems in the future if he continues this way. Additionally, they're also concerned about his emotional well-being, as they believe he might be using this new relationship as an escape from dealing with his grief. They're also worried that there might be a biological reason for his sudden change in behavior, as sometimes, especially in older folks, there can be a brain or biological reason that people start acting differently.