By Amber Goodhand - Breaking Celebrity News News Editor

Adrienne Maloof and her husband filed for separation on Monday, but Breaking Celebrity News has exclusively learned the couple were having issues for a long time and even had an open marriage.

The Real Housewives of Beverly Hills star's estranged hubby Dr. Paul Nassif has already moved out of the family mansion, but friends of the couple are not surprised by the split and even say they saw it coming.

"Adrienne and Paul have pretty much had an open marriage for quite some time," a close pal exclusively told Breaking Celebrity News.

"They both knew of indiscretions the other had, and both would get jealous, but their marriage had become so broken it was the only option for them."

After nine years of marriage, Adrienne exclusively told Breaking Celebrity News: "I'm so sorry that this is happening, but my children are my life and sometimes we need to do what's best for them. It's an unfortunate situation, but I have to have my kids' best interest at heart."