LA-based Robbie also said he is best friends with Jill Zarin from the TV reality hit, The Real Housewives of New York City.
Robbie, 36, told Aussie radio show 2DayFM in a phone interview how he confused Joel with Benji Madden from the band Good Charlotte.
And he also dismissed recent reports he had laughed at Kylie Minogue when he saw her naked as they made their video for the song Kids.
But asked by a fan on Sydney’s 2DayFm radio station if sex stopped after marriage, he replied, 'Not so far. So far so good. We're having nice times.'
Robbie was also asked if he wanted a boy or a girl. He replied, 'I want a gay one.'
He said, 'I always thought, 'I want a boy, I want a boy', but now I'm like, 'A girl would be a daddy’s girl'.