Three's Company - Season 1 Episode 2
And Mother Makes Four

Jack is all set to move into Eleanors room, until Chrissys mother unexpectedly shows up. Chrissys mom does not know that she and Janet live with a man, so she tries to keep them out of sight. Janet and Jack go to the Regal Beagle to hide out, and Mrs. Roper finds out that Jack is not really gay. She manages to keep it secret from Mr. Roper.