Comedy about a man living a double life with two families for 20 years? Movies with such serious seeming themes are not made for comedies. Walking the line if a tough act which, when accomplished, usually results in classic type black comedies. In this case Frank's writers pull it off in fun and also serious fashion. Son Philip and dad Frank are both likeable and do well acting. The remainder of the cast also does well. The writer(s) win the day crafting a dandy back story and current goings on. Frank's effort to convince his son Philip that he did the 'right' thing, embarking on a double life, given the circumstances. What else was a man to do!

The writers missed a final fun twist. They could have had wife #2 announce her first child was not Franks removing a major obstacle to sibling love.

That aside, well done!