Kristin Cavallari, 33, and Jay Cutler, 36, have called it quits, and while a breakup is typically a somber event, it doesn't stop fans from speculating what happened to cause the demise of the relationship. Fans have an idea about the couple's marriage struggles because of their E! reality show "Very Cavallari," but an insider recently provided some clarity as to what went wrong.

"Kristin and Jay had been having problems for a long time. They hadn't spent much time together in recent months," the source told People.

The source added that the decision to divorce had "absolutely nothing to do" with rumors of the ex NFL quarterback cheating with Cavallari's former best friend Kelly Henderson.

"Kristin and Jay are a lot different. She has so much on her plate, with her brands and with the show," the source explained of their split. "Jay is not as interested in all of that. She's so passionate about her work and they couldn’t relate to each other as much. So it pulled them apart."

The news may come as a bit of a shock to some as Cavallari and Cutler were recently enjoying a vacation with family and friends, but the insider revealed that they had already decided on what was to come.

"On their recent trip, they already knew they were splitting up," the source said. "The reason they announced it now is because it’s a quiet time for them to work through all of this and try to move forward."

 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

A post shared by Kristin Cavallari (@kristincavallari) on

On Sunday, the former "The Hills" star announced her and Cutler's plans to get a divorce after seven years of marriage and a decade-long relationship.

"With great sadness, after 10 years together we have come to a loving conclusion to get a divorce," Cavallari captioned a post of the couple walking into the distance.

"We have nothing but love and respect for one another and are deeply grateful for the years shared, memories made, and the children we are so proud of," she continued. "This is just the situation of two people growing apart. We ask everyone to respect our privacy as we navigate this difficult time within our family."

The "Very Cavallari" couple share sons Camden, 7, and Jaxon, 5, and daughter Saylor, 4.

Kristin Cavallari
Kristin Cavallari married former Chicago Bears quarterback Jay Cutler in 2013, and the pair are now parents to sons Camden and Jaxon, as well as a daughter, Saylor. The couple have since planned to leave Chicago following his being cut from the team. Here they are pictured at the Michigan Avenue Magazine’s Fall Fashion Issue Celebration in Chicago on Sept. 9, 2014. Jeff Schear/Getty Images for Michigan Avenue Magazine