The Honeymoon Is Over was created in 1993-05.
Honeymoon's Over - 2010 SUSPENDED was released on: USA: 2010
The honeymoon is over when 3 bushels of kisses are reduced to a peck.
It means your relationship with him is over.
This doesn't seem to be a slang or idiom according to my search engine. A honeymoon is the period of time right after you are married, when everything seems wonderful and happy. Perhaps that is what the person meant.
The Honeymoon's Over - 1939 was released on: USA: 14 December 1939 (New York City, New York)
Providence - 1999 The Honeymoon's Over 4-7 was released on: USA: 9 November 2001
My Three Sons - 1960 The Honeymoon Is Over - 10.21 was released on: USA: 28 February 1970
227 - 1985 The Honeymoon's Over 3-9 was released on: USA: 28 November 1987
Step by Step - 1991 The Honeymoon Is Over 4-15 is rated/received certificates of: Argentina:Atp
Petticoat Junction - 1963 The Honeymoon Is Over 5-12 was released on: USA: 25 November 1967
Step by Step - 1991 The Honeymoon Is Over 4-15 was released on: USA: 3 February 1995