EXCLUSIVE: Katherine Heigl Re-Teams With Husband Josh Kelley for Emotional Directorial Debut -- See the New Mu

Katherine Heigl is baring it all with her directorial debut.

The 37-year-old actress strips down to her undies alongside her husband, singer-songwriter Josh Kelley, in the new project, but the couple is also getting candid about a rough patch in their marriage.

WATCH: Katherine Heigl Sings (For Real!) in 'Jackie & Ryan' 

Only ET was on the set of Kelley's music video for his new single, "It's Your Move," where the singer’s wife directed and co-starred.

"I think it was a year or two after we first got married, we got into our first real big fight. One of those, like, really, really serious fights," Kelley says of the song's inspiration.

"No one cheated, no one did anything that was an absolute game-ender," Heigl adds. "It was just that we were starting to forget that we were supposed to be on each other's sides. ... And I won't lie, there was probably a little bit too much drinking going on, and so then the fights escalate and the miscommunication and the hurt feelings."

The couple recalls the fight as "a healthy one," and now the song is featured on Kelley's forthcoming full-length album, New Lane Road, out April 22. See the full video below!

WATCH: Katherine Heigl: 'I am a Strong Woman and I'm Not Going to Apologize for That' 

Heigl says that putting the video out into the world has been a "cathartic" experience for their marriage.

"He came home and played [the song] for me and I went, 'Oh, that's how you feel. That's what you mean and that's where you're at emotionally' and it was so crazy to me," she recalls. "I think it was the first time I fully understood, 'Oh, Josh,' you think he's not feeling all these complicated emotions, he's just kinda being a dude about a lot of stuff, and then he comes in with this gorgeous poetry and this heartfelt emotion. I realized, 'Oh, that's how I can understand what Josh is thinking and feeling. That's how I have to touch in with him, through his music.'

"Obviously, we worked it out, thank goodness," she adds. "But it's so interesting to be here now, you know, kinda full circle."

"It's Your Move" does indeed mark a full-circle moment for Heigl and Kelley, who first met 11 years ago on the set of his 2005 music video, "Only You."

"I remember showing up like, 'Ooh, I'm single, I've never dated a musician. This could be fun!'" Heigl teases. "I was excited to meet him and he was like, 'Hey, thanks for being here. Appreciate you being here. We're gonna have a fun day.' I was like, 'OK, guess that's not gonna happen. There will be no flirting or fun or maybe a makeout session later, like, this guy's not interested.' But as the day went on, his nerves kinda lessened. We started dating that day and never stopped."

"It was hard not to notice the fact that she's super-hot," Kelley quips. "Then when we started doing our scenes together, we just had this chemistry and, I don't know, it was this weird, sort of unspoken connection. We've literally been together since that day. I remember after the video shoot, I asked her out to dinner and we just kinda hit it off -- very organic and very effortless."

Two years later, in December 2007, the pair made it official and tied the knot. Today, Heigl and Kelley live on a farm in Utah where they are raising their two daughters, Naleigh, 7, and Adalaide, 4.

"We live a very normal, simple life. I love being a dad, I love being a husband," Kelley gushes. "It's just one dude and a ton of chicks!"

Those "chicks" have been very involved as Kelley's inspiration for his first new music in over five years, which he wrote and recorded at the family's home studio.

"It's a boundary-less album," Kelley says. "People consume all kinds of different styles of music and all I really focused on was trying to write really great songs and not focus on writing in a specific genre. Just write something that I really love, and hopefully, if I love it, then people will love it as well. ... I write about what I know, and right now, all I know is raising kids and being a husband and a handyman, the AV guy. It's hilarious."

New Lane Road is available for pre-order now, while Kelley will join his brother, Lady Antebellum's Charles Kelley, on The Driver tour this spring.

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