"We were totally separated before I moved on," he told People, adding that he and his wife of 20 years have been separated "for a while".
It was also claimed that Zach's wife was left "shocked" by his relationship with Paula, especially as he decided to move in with her shortly after they began dating. However, Zach responded to these claims by insisting there's always different sides to a story.
"Obviously there's three sides to every story and I'm not pointing the finger or saying anyone's wrong, but we were definitely separated before I moved on," he explained.
Paula, who split from Robin Thicke in 2015 after a decade of marriage, recently made the revelation she has a new man during a chat with news outlet Extra earlier this week, but refused to name names.
"I have a boyfriend now," she gushed. "I haven't called anybody a boyfriend. He's my boyfriend! But when you know, you know. I love him." Revealing they have been dating for a month, Paula suggested she had met Zachary while on a sports outing with her eight-year-old son Julian, whose dad is her ex.