Jen's Heartbreak! Aniston Catches Justin Theroux Making Secret Calls To Ex Lover

Jennifer Aniston and Justin Theroux are no longer in the honeymoon stage of their marriage. RadarOnline.com has exclusively learned that the actress busted her husband making phone calls to his former lover – and the scandal could rock their marriage with $170 million at stake!

The Leftovers star has been accused of making calls to costume designer Heidi Bivens, 39.

"For months, Jen has been suspicious that Justin was communicating with Heidi," a source told RadarOnline.com of Theroux, 44, who has been friends with Bivens for 14 years.

Aniston, 47, busted her husband when an unfamiliar New York number called his cell phone. When she asked about the call, he said it was, "A friend who you don't know."

Worried her husband may meet up with the mystery caller during a solo trip to New York, the Mother's Day star dialed the number and recognized the voice. 

"Jen confronted Justin," the insider revealed. "She broke down in tears and demanded that he cut off communication with Heidi immediately. Justin tried to apologize and made a few lame excuses about he and Heidi having mutual friends."

Although the actor denied her claims, Aniston "feels destroyed" by her husband, whom she wed in 2015.

Aniston met Theroux in 2007 when he was still living with Bivens. The actors reconnected in 2010 on the set of their film Wanderlust. Although Theroux was still seeing Bivens in May 2011, he and Aniston confirmed their relationship in June.

The source said, "This is the ultimate betrayal for Jen and her absolute worst nightmare."