All dreams are collages of real life. The dreamer may see the plot of an affair in TV series or news, and unconsciously connect with his father in his dream. This is the subconscious at work, probably because he loves his family very much and is afraid that one of his parents will have an affair and destroy family harmony. It is also possible that the dreamer has encountered such a thing in his life (but it happened to others).
In short, dreams have no practical significance. Don't change your life for a strange dream. Only people with special abilities have the ability of prophetic dreams, but such people are rare in the world. So please don't worry.