Is it the seven-year itch that is to blame for Jennifer Lopez and husband Marc Anthony recently announcing that they are to split after seven years of marriage? Recent divorce statistics in the States show that first marriages are most likely to end up in the divorce courts eight years after a couple say "I do".
The initial separation proceedings are instigated after seven years of marriage.
It seems that for all that has changed about marriage statistics since the 1950s -- the age at which people marry is getting older, and the divorce rate has risen and fallen -- one number has remained static: a couple is most likely to split around the seven-year mark.
Lopez (42) and Anthony (42) became a couple in early 2004 after Lopez broke up with Ben Affleck, and Anthony was divorcing former Miss Universe Dayanara Torres.
They married in a small ceremony in 2004, and have three year-old twins together, Emme and Max.
Is superstar Lopez, who was back in the spotlight this year as an American Idol judge, a victim of the seven-year curse?
It's 56 years since Marilyn Monroe moved into the same apartment building as a happily married man whose wife -- of seven years -- happened to be away for the summer, and The Seven Year Itch, as the film was titled, is still with us.
Reasons given for a couple splitting in and around this time include the stress of caring for young children, the accumulation of bad times, and work and family pressures, all of which tend to build to a boiling point around seven years.
Typically, people who are unhappy with their marriages find that out within the first few years, yet take a few more years to get to the state of divorcing.
Most divorces are instigated by women. The average woman marries in her late 20s or early 30s, and when things go wrong she is likely to think: "I need to get out before I'm too old. I'll have more options if I'm 35 versus 45."
The current understanding of the phrase "seven-year itch" was popularised in 1952, when the late playwright George Axelrod used it as the title of his play about a couple divorcing.
Other couples who seem to have suffered the seven-year itch include Macaulay Culkin (30) and Mila Kunis (27). They never married, yet Culkin, former child star of Home Alone, had set up home with the actress Kunis, who will soon be seen in Friends with Benefits.
The couple, who split in January, were very low key and rarely walked the red carpet together. They first met when Kunis was starring in That 70s Show. Kunis is now one of Hollywood's rising stars, following rave reviews for her appearance in the hit movie Black Swan.
Another Hollywood couple who hit the skids after seven years of marriage is Oscar winner Kate Winslet and director Sam Mendes.
Titanic star Winslet (35) and her ex-husband and American Beauty director Mendes (46) married in May 2003 on the Caribbean island of Anguilla. Their son, Joe, was born seven months later.
The couple split last year and their lawyers insisted that there was no one else involved. A statement said: "The split is entirely amicable and is by mutual agreement. Both parties are fully committed to the future joint parenting of their children."
Financial problems can start to rear their head for an average couple after about seven years. The honeymoon period is over and family relationships with children, parents, in-laws, siblings and step-children can all be sources of marital problems.
Problems with sexual frequency, quality and infidelity are also common reasons for marriage failure and divorce. Negative personality traits make a long-term relationship unbearable, and divorce an attractive possibility.
While last but not least, if you want to avoid the seven-year itch, make sure you and your partner have similar lifestyle expectations. Partying all night while the other prefers quiet nights in is quite the passion killer.