Continuity mistake: In season 2's episode "The Ricardos Change Apartments" their new apartment number is "3B", but in this episode when Lucy's at her audition she tells the casting agent that her apartment number is "3D" (deliberately done in order for the 3D joke to work), and it's in the next episode "The French Revue" that we see the new number "3D" on the door. (00:19:30)
Visible crew/equipment: When Lucy and Ethel are at Caroline Appleby's apartment, a few actors' tape marks are visible on the carpet near the couch and side table, where characters will stand at different times during the scene. (00:06:00)
Answer: According to Snopes.com, there is no definitive answer, but the mid-1960s is the most verifiable date with "The Munsters" being cited as the first, although others claim "The Brady Bunch" showed the first couple seen in a double bed. An early TV show from the late 1940s titled, "Mary Kay and Johnny" is also thought to have shown the married couple's bedroom as having a double bed, although probably not with them in it. However, this was when TV was aired live, and there are no surviving episodes, only anecdotal accounts.
raywest ★
Something that is funny is that in the movie "A Christmas Story," they show the parents having two twin beds in their bedroom. In a real situation, they should have shown them having a double bed. Lucy and Ricky had twin beds pushed together in an early episode, which would have been pushing television boundaries in that time.