Who is Mac McPhail from That Summer and what is their importance?

Mac McPhail is Haven and Ashley's dad who cheated on Mom with Lorna Queen, the Channel 5 weather girl. He is a sports anchor for Channel 5. Dad marries Lorna at the beginning of the novel, and they announce they are pregnant near the end. He takes Haven to dinner every Thursday night, tries to push his daughters to like Lorna and offers them money constantly to make up for his daily absence.