The 'Blurred Lines' hitmaker had earlier dedicated an emotional song to Paula, 38, at one of his concerts in a bid to win her back, reported People magazine.
"We're both doing well. We're both very happy right now, much happier," he said.
"My music is very honest about what I'm going through and my songs are about my life. And my relationship with her was 21 years of my life, so I just thought it was important to me to let people know how much she means to me," he added.