Season 4: Episode 97: Papa's Got a Brand-New Excuse
Will's long-lost father, Lou, breezes into town and promises Will the moon, which angers Phil and Vivian, who give him the cold shoulder for walking out on Will and Vy. When Will was 4 years old, his father went to get a pack of cigarettes and never came back. Years later he became a trucker, but Will was going to college by then. When his father abandons him a second time, Will accepts the fact that Uncle Phil is the closest thing to a father that he has ever had.