Sanford and Son - Season 6 Episode 25 School Daze
Overview: Fred has been neglecting Donna and she decides to investigate and soon discovers Fred has been leading a secret life, not even telling Lamont what has been going on. Donna is convinced that he is seeing another woman but they soon discover Fred is really going to night school to earn his GED diploma, which he never got since he dropped out of high school to support his parents.