In a new interview with Vanity Fair, the 49-year-old actor unashamedly admits that Byrne, 40, makes twice as much money as him.
"I make half as much as she does," Cannavale, who shares two kids, Rocco, 3, and Rafa, 2, with Byrne, proudly says of their pay disparity. "Down the middle. Half. I work too much in the theater, perhaps."
Over the seven years that they've been a couple, Byrne and Cannavale have worked together a total of five times, in films like Annie, Spy and Adult Beginners. In 2020, they'll take that number up to seven, starring in Brooklyn Academy of Music's Medea and the Sydney Theatre Company's A View From the Bridge.
"It starts out as a very pragmatic thing," Cannavale explains, of why he and Byrne say yes to the same projects. "You have the kids, the kids are getting bigger, and you don't want to spend the time apart."
The outlet also reached out to a few of the couple's former colleagues, who spoke to what makes Cannavale and Byrne's love so unique.
"Rarely do you find two people who are equally talented and unique and singular voices in their space, who work well together -- and in such a variety of projects," Nick Kroll shares.
"The chemistry between them, it's just so remarkable," Glenn Close adds. "They’re both kind of universally loved."
Speaking with InStyle back in 2017, Byrne also opened up about what it was like collaborating with her partner over the years.
"[It's] a little bit [intention and coincidence]. A happy coincidence in some ways, and also, 'Let's really try to get these parts so we can be together and working,'" she said at the time. "We did, like, three projects in a row, and I enjoy collaborating with him."
"[Bobby] is one of a kind, man!" she added. "He's endlessly interesting and entertaining. When something is special, it’s hard to articulate it, but I feel really lucky. We couldn't be from more different parts of the world, you know?"
Hear more on the usually private lovebirds in the video below.