I think the Nortons on
The Honeymooners
also slept that waywith their twin beds pushed together. The only time their beds were shown, however, was in the episode in which Ed and Ralph slept together (when Ed was sleepwalking). I guess just the notion of having one double bed was off-limits; two twin beds together was more wholesome (or maybe it was assumed that the beds would move apart on their own if the action got too energetic?).
I'm not crying, you fool, I'm laughing!
Hewwo.

Actually, the first 2 seasons they slept on twin beds pushed together. However, after little Ricky was born, they separated the beds to reduce the sexual relationship.how dumb was that? (LOL)

Lucy and Desi also slept in twin beds on
I Love Lucy
.
I'm not crying, you fool, I'm laughing!
Hewwo.

The only couple I could think of that didn't sleep in twin beds were Lucy and Desiof course they were married in real life.

You can blame the Hayes Code for the Twin Beds. NO ONE slept in a double bed on TV or films from the late 1930s through 1960s? sometime.
And there were a lot more equally absurd rules.

I was about to make this comment but my temporal self beat me to it, 3 years ago.

So once again it is the cartoons that push limits for puritans.

The answer to this question TV couples in a double bed keeps getting updated, but here is what I have been able to dig out:
Mary Kay and Johnny1947
The Flintstones1960
The Munsters1964
Please Don't Eat The Daisies1965
The Brady Bunch1969 (Florence Henderson thought they were the first)
After that, it started being more of a norm than the exception.
I also seem to remember that in the last season of Get Smart, when the spies were finally married, they slept in a double bed, except for one episode where 99 is replaced by a double. Because the script called for her to be in the apartment overnight, suddenly the Smarts were sleeping in twin beds!

I believe The Flintstones were the first couple shown in bed (seriously). I know the Hayes Code was trying to promote morality, but double beds was taking it too far.

The censors wouldn't allow a married couple to be in the same bed back in the day. The Munsters was the first show to change that.

Maybe they decided on double beds because he is a doctor..therefore he probably left in the middle of the night for emergencies..and he didn't want to disturb his wife.

To my knowledge, they couldn't show couples back then sleeping in the same bed.
No good deed goes unpunished.