The 'Angels' hitmaker - who rekindled his Friendship with his Take That bandmate last year after over a decade of animosity - is now so close to the singer, his spouse Ayda Field fears she has a rival for his affections.
When asked how he had found working with Gary again on their new duet 'Shame', he said: "It was amazing. Not awkward at all, I love him to bits. Ayda calls him my boyfriend."
However, the 36-year-old star is smitten with his new bride - who he married in an intimate ceremony earlier this month - and still can't believe how "magical" his wedding day was.
He added: "It was the best day of my life. Being married rocks. We're A Team. i wasn't expecting the day to be as magical as it was."
Ayda is a big fan of her husband's music and was thrilled when he penned a track for her on his most recent album, 2009's 'Reality Killed The Video Star'.
Asked what the actress' favourite song of his was during a twitter webchat with fans, he replied: "Won't Do That To You. Reality Killed The Video Star."
The singer - who has a history of drug and alcohol abuse - also told fans how much his life has improved in recent years.
He said: "Life does get better in your 30s, you find out who you really are."
Robbie and Gary will perform 'Shame' at the Heroes concert at Twickenham Stadium in London on September 12.