Details Emerge on J.Lo and Marc Anthony Split

INSIDE EDITION is learning more about what led J.Lo and Marc Anthony to call it quits.

Friends close to the couple tell the new issue of People magazine that the divorce was many months in the making.  

Tensions in the marriage escalated when Lopez became a judge on American Idol.

"A source said that Marc had become very envious of all the attention she was getting on American Idol. But an Anthony insider said he always supported her career," senior People writer Joey Bartolomeo said.

In public, Anthony seemed totally supportive. He even sang with her during an incredibly steamy performance at the Idol finale in May. But behind the scenes, trouble loomed.

"Jennifer had often kicked Marc out of the house, he'd been staying at hotels. By Fourth of July weekend, he left on his own," said Bartolomeo.

And the magazine says they both suspected each other of cheating.  A source says Anthony was jealous of his wife's relationship with William Levy, the hunk in her new music video and that he "would go crazy every time [Levy] was mentioned."
 
But People also reports: "Jennifer suspected Marc was not faithful, and it's been eating away at her."

By the time she took a trip with her children to Disneyland in June, she "seemed to make up her mind she wanted to end the marriage."