"We've [been] on a trial separation for a while now," Arquette told Stern and his co-host, Robin Quivers, during Stern's Sirius Radio show on Tuesday (October 12).
Arquette told Stern that he and Cox had not been intimate for months. "I completely understand," he said. "She's in a place of wanting to be real and emotional. ... She's an emotional being, she's an amazing woman. If it doesn't feel right, she doesn't feel like bonding in that way."
Arquette went on to admit to having sex with another woman, a reversal from a statement he gave to reporters a few months ago.
"We have a really great, beautiful relationship," he told People in June. "Whenever things come up, we deal with them. We communicate. I would never do anything to jeopardize our relationship, you know what I mean? I'm committed, and we're honest with each other. ... Relationships take a lot of work."
Cox, on the other hand, revealed that she and Arquette had been to couples therapy. "We've done couples therapy in the past," she said in an interview published in the July issue of InStyle. "We're not lazy about our marriage. We have the same arguments we've had for years."
According to TMZ, a source close to the couple — who met on the set of the original "Scream" in 1995 — claims Cox and Arquette are "still friends" and maintain a business relationship.