"We're not having sex, and I completely understand," Arquette, 39, 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."
Cox, 46, wants him to grow up, he added. "She says that to me: 'I don't wanna be your mother anymore,' " Arquette said. "I appreciated that. I respected that. I've been going to therapy. I'm trying to grow up."
Arquette called Cox, 46, his "best friend," and added: "She's the greatest woman I've ever met … Now, yes, she's got her issues. She tries to take on everybody's problem. She tries to be the mother to everyone – that's why she doesn't want to be the mother to me anymore."
After 11 years of marriage, the Hollywood pair said in a statement this week that they have "agreed to a trial separation that dates back for some time." They have a 6-year-old daughter Coco, together.
"The reason for this separation is to better understand ourselves and the qualities we need in a partner and for our marriage," they said.