Angie Harmon of Rizzoli & Isles fame and her hubby Jason Sehorn called it quits this past weekend after 13 years of marriage. What happened to cause a marriage with that longevity to fail?

A source told Us Weekly that the split was actually in the works for a while. It didn’t just happen over the weekend.

“A large part of it is when you spend five or six months a year away from your spouse, it gets really tough,” the source explains.

It seems Angie Harmon wanted to raise the couple’s three children–Finley, who is 11, Avery, who is nine, and Emery, who is five–in North Carolina. Rizzoli & Isles is filmed in Hollywood.

“In the beginning, they really missed each other,” the source says of Harmon and Sehorn, “but then they got into a groove where one person took over the main responsibilities of parenting while the other was working.”

“She didn’t want them growing up in Hollywood and being exposed to the fast-paced life,” the source added, noting that Angie Harmon firmly believed the living situation was the “greatest thing” she could do for the children.

The distance between Hollywood and North Carolina is great, and the work relegated to the former NFL player might have become too great. Jason Sehorn spent most of his time staying home and caring for the children while Angie Harmon went off to California to work.

Hometown actress Angie Harmon and NFL player Jason Sehorn split http://t.co/y2M71qYysR via @AlanPeppard pic.twitter.com/owYunRmVmU

— Dallas Morning News (@dallasnews) November 4, 2014

The source is quick to point out that neither cheated on the other. In fact, neither betrayed the other in any way at all.

“They’re good, devout Christian people,” the source said. “The split wasn’t shocking to their close friends.”

It was likely clear to those close friends that Jason Sehorn was simply unhappy with the way their lives turned out.

Angie Harmon’s rep confirmed on Monday that the two were splitting up.

“For the sake of their children, they ask for respect and privacy as they navigate this time in their lives,” the rep said.

It’s sad to see a 13-year-old marriage fail. Hopefully Angie Harmon and Jason Sehorn will find a workable way for both to spend time with their children, and to make this huge adjustment as painless for them as possible.