The Duets mentor told The AP that he constantly rejects music requests from Patton, who has collaborated with Usher in the past.
Thicke quipped; "She'd be like, 'Hey, baby, can I just sing a little song just so I can hear my voice on tape?' And I was like, 'No! We're not starting that. We are not going to get into the "you recording an album". Go find another producer if you want to do that!'"
The singer then revealed that Patton does share a vocal similarity with the iconic Marilyn Monroe.
"She does a mean impression of Marilyn Monroe's 'Diamonds Are a Girl's Best Friend'," Thicke revealed. "But nobody is allowed to see that. That's just for daddy."
Patton and Thicke have been married since 2005.
Thicke previously claimed that he considers himself to be the "underdog" on his new reality competition Duets.
Watch Robin Thicke's 'Lost Without U' music video below: