RadarOnline reports that the two have been "unhappy for years," and that Rhea was getting angrier and angrier over Danny's womanizing ways. "He may not appear to be a ladies’ man, but Danny certainly gets a lot of female attention," a source said.
"Despite his reputation as a lovable, funny guy in movies and on TV, Danny’s actually quite the womanizer. And, like a lot of red-blooded males, if he sees an attractive girl in a coffee shop or walking down the street, he will give her the eye.
"After years of turning a blind eye to it, Rhea finally snapped. She had enough of his bad-boy behavior and wanted an end to their marriage."
The source also said that the two have been unhappy for almost 10 years.