The grass is always greener ?

Lauren Bacall & Marilyn Cooper appear to have started off this craze in the Broadway show "Woman Of The Year" in 1981. Based on the 1942 Katharine Hepburn-Spencer Tracy film of the same name.
Seemingly:
"Tess Harding, a nationally-known television news personality, comes on stage to receive an award as "Woman of the Year", she reminisces about an on-air editorial that she gave denigrating newspaper comic strips. The article offended the cartoonists who frequent the Ink Pot saloon and inspired syndicated cartoonist Sam Craig to publish a caricature depicting her as a snob in his strip Katz. Tess is annoyed, but when the handsome and charming Sam shows up at her office, she apologizes and invites him to dinner. At the Ink Pot, she charms Sam and his colleagues by revealing her knowledge about comic art."

I won't bore you with rest since the title song has lines including the quite unforgettable:

First you find her diaphragm,
Ah, the grass is always greener,
Where some other tenant pays rent,
Ah, the teeth are always cleaner, In someone else's Sterident,
do you know who your neighbours are?

Despite rave reviews many humans decided that the Broadway play was a complete turkey. However it has remained a firm favourite of a great many horses in the shire who relish the green grass of the home next door.