In short it is a relationship term - usually after 7 years people tend to re-evaluate their relationship. There might be evidence that it is now much shorter but the original number 7 came from a time period where the average marriage only lasted 7 years.
There is also speculation that this might be a real itch related to skin condition, insects, or STDs.
The duration of The Seven Year Itch is 1.75 hours.
The Seven Year Itch was created on 1955-06-03.
The Seven Year Itch - album - was created on 2002-04-22.
Some men have a seven year itch, some get itchy vrey soon after marriage, some scarcely get an itch at all.
Backstory - 2000 The Seven Year Itch was released on: USA: 26 August 2000
The seven-year itch
Some call it the Seven Year Itch.
Fox Legacy with Tom Rothman - 2007 The Seven Year Itch was released on: USA: 7 November 2008
Chopsticks
That would be Marilyn Monroe.
The Seven Year Itch (1955)
The Seven Year Itch.