The couple have announced they were separating after nearly nine years of marriage yesterday.
And sources tell Us Weekly their union has been disintegrating for a while now.
"Their marriage was unravelling for a long time," an insider said, with another source echoing: “It has been a long time coming.”
Paula, 38, and Robin, 36, have reportedly been discussing the inevitable end of their partnership openly with one another.
And since the estranged spouses weren’t caught off-guard by their split, they’re apparently better equipped to maintain a sense of normalcy for their three-year-old son Julian.
Oscar-winner Jennifer Lawrence and Coldplay frontman Chris Martin have split after four months together
Kelly Brook has ended her engagement with former Gladiator David McIntosh after a whirlwind romance
Model Amber Rose and rapper Wiz Khalifa announced they will be filing for divorce after being married for just one year
Tea Leoni andDavid Duchovny have reportedly divorced in secret after 14 years of marraige
Former Miss Ireland and rugby star Cian Healy split after two years together
The Hills star Audrina Patridge and Corey Bohan have called it quits after five years together
Model Hayley Ryan and Dave Kearney have parted ways after nearly three years together
Jennifer Lopez and Casper Smart have split after two and a half years together and a sexting scandal
Modern Family actress Sofia Vergara and ex Nick Loeb
Glees Naya Rivera and fiance, rapper Big Sean have ended their engagement after just a few months
Gwyneth Paltrow and Chris Martin
Robin Thicke and Paula Patton announce their split after nearly nine years of marriage (Photo by Dan MacMedan/WireImage)
Marc Anthony and Chloe Green
Heidi Klum split with her bodyguard boyfriend Martin Krist due to poor timing.
Calvin Harris and Rita Ora pose during the MTV EMAs 2013
After just three years of marriage, Hilary Duff and Mike Comrie have decided to split - they have one son together Luca Cruz (2)
Khloe Kardashian and Lamar Odom
Supermodel Miranda Kerr and actor Orlando Bloom have confirmed they have ended their marriage. They have a son, Flynn, together.
83-year-old Clint Eastwood split from his wife Dina after 17 years of marriage. Clints refusal to slow down and Dina's reality show were reportedly factors in the split.
Tamzin Outhwaite and her husband Tom Ellis separated after seven years of marriage. Outhwaite, 42, and Ellis, 34, got married in June 2006, a year after meeting. They are parents to four-year-old Florence Ellis and one-year-old Marnie Mae Ellis.
Actors Chris Evans and Minka Kelly have split after just over one year together.
Catherine Zeta Jones and Michael Douglas have separated after more than 13 years of marriage.
Kelly Brook and Danny Cipriani broke up (again) when Kelly (33) discovered Danny was cheating on her after finding messages on his phone.
After initially forgiving her her indiscretion with married director Rupert Sanders, it appears that Rob can't forget. The two are said to have now split after a rocky few months.
Nicole Scherzinger and Lewis Hamilton split after five years together, with sources close to the couple saying that the long distance nature of their relationship was too much pressure to sustain.
Rachel McAdams and British actor Michael Sheen split earlier this year, which left McAdams "heartbroken" as her long-term boyfriend didn't want to settle down.
The pair had been together for 14 years and are the parents of two children. Johnny has been since linked to actress Amber Heard.
TV3 star Sinead Desmond split from her husband David Ryan of four years. She said there is no one else involved, although Sinead recently admitted in an interview that the pair slept in separate rooms becuase of her schedule.
Kathryn Thomas and Enda Waters marked one of the most shocking splits in Irish celeb land late last year after five years together.
Sile Seoige and RTE floor manager Kim Burrows were together for two years before parting ways last year.
They were thought to have on of the strongest relationships in the business. But alas the couple have split and the supermodel is now dating her bodyguard, Martin Kirstin, whom Seal referred to as The Help.
There had been rumours for ages that all was not well in Tom and Katies marriage of five years. Nonetheless, when their split was announced it still came as somewhat of a surprise. The bets are on as to who Toms next wife might be.
Myleene Klass and Graham Quinn - no one saw this coming, after just six months of marriage the couple who were together 11 years have parted. The TV presenter later revealed she was heartbroken after the split.
Rugby star Rob Kearney and his girlfriend Susie Amy split after three years together. Location, location, location is what one source blamed for their break-up.
After 14 years of marriage, the former Boyzone star and his model wife ended their union, following Ronan's confession of infidelity. Both are now in new relationships: Ronan with TV producer Storm Uechtritz, and Yvonne and cameraman John Conroy.
The 52-year-old X Factor supremo split with the make-up artist, ending their wedding plans, after a series of rows. It was reported that Simon promised to transfer ownership of his 5 million Beverly Hills house to Mezhgan for being a 'hopeless boyfriend'.
Mollie King and David Gandy have reportedly ended their relationship
Was it the age difference that proved to be their downfall - Delta is 27 to Nick's 19. Whatever it was, the couple announced they had split in February of this year after dating for nine months.
The TV star split from her husband in 2010 after 10 years of marriage. She is now involved in a relationship with South African rugby coach, Leon Jordaan.
Westlife star Mark Feehily dramatically split up with his partner of seven years, Kevin McDaid. The pair were engaged but early last year, Mark announced the couple had parted ways.
Twilight actor Peter and his wife of 11 years, 90210 star Jennie, surprised everyone when they split. Peter filed for divorce last year and they couple sought joint custody of their three children. Jennie was subsequently forced to defend her dramatic weight loss, post-divorce and Peter is dating actress of the moment, Jaimie Alexander.
The formerX Factor judge and her boyfriend split last spring after four years together. The couple have a young song, Ethan.
The Spice Girl had a 10-year relationship with property developer Thomas before they split last summer. The couple have a 3-year-old daughter, Scarlet.
The former Playmate and her musician boyfriend were engaged for four years but called it off in autumn. Carmen was seen smooching Simon Cowell for a while after the split.
The Gladiator star and his wife of nine years called it quits at the end of 2012. The couple have two sons, aged six and eight.
The actress and designer Jason are parents to 16-months-old Arthur but split earlier this year after two years together.
Jamie Campbell Bower and Bonnie Wright - the 23-year-old actor and the 21-year-old actress met on the set of Harry Potter and the Deathly Hallows. They were engaged for a year before going their separate ways in June - too much too soon?
Are they or aren't they? Or are they one of those elusive couples who managed to stay friends after a split? The Script's Danny O'Donoghue and model Irma Mali ended their three year romance last year, but are still often spotted together.
"It is not a shock to Robin or Paula, and it is something they have discussed for a long time,” an insider revealed.
Paula and Robin began dating when they were both teenagers and married in 2005.
In her separation statement, The Mission: Impossible actress insisted she and Robin will remain close in spite of their breakup.
"We will always love each other and be best friends, however, we have mutually decided to separate at this time," Paula told People magazine.
There was speculation their marriage hit a rough patch when Robin performed a raunchy routine with 21-year-old
Miley Cyrus at last year’s MTV Video Music Awards.
But apparently this isn’t why their union ended. A source tells E! News the Miley twerking scandal was a “non-issue” for the couple.
Around the same time as the MTV VMAs in August 2013, Robin was accused of cheating on Paula at a party. But the couple publicly insisted their marriage was passionate and strong even after the scandal hit.
"The spice is not our problem," Robin told America’s Elle magazine in October. "We're overspiced.”