Frazer Harrison/Getty Ashton Kutcher
In a clip from Kutcher's new Peloton running series, Our Future Selves, the That 70s Show alum, 44, shared how he broke the news to his now-wife with the help of his guest, country singer Kenny Chesney.
"The first time I told my wife that I love her, was while listening to 'You and Tequila,'" Kutcher said in a clip shared to Peloton's TikTok account Tuesday of him running alongside Chesney, 54, on a treadmill.
"I might have had a little too much tequila," he jokingly added in the 10-part series from Peloton where Kutcher welcomes various guests to join him as he trains for the 2022 TCS New York City Marathon.
"I showed up drunk at her house, at like two in the morning, and I just started screaming, 'You and tequila make me crazy,'" continued Kutcher. "And I told her I love her, and she's like, 'Don't say it if you don't mean it. Are you gonna love me in the morning when you wake up from this hangover?'"
The following day, Kutcher confirmed to Kunis, 39, that his feelings were legitimate. "I woke up the next morning and said, 'I still love you,'" Kutcher shared.
In response, Chesney told the actor that the story was news to him. "Well, I had no idea that me and Grace Potter were such a part of a really intimate detail for you and your wife," Chesney said of the song which features the 'Empty Heart' singer.
Stefanie Keenan/Getty Ashton Kutcher and Mila Kunis
"You and Grace Potter brought it home," Kutcher added. "These are fundamental moments in my life"
Kutcher and Kunis first met as costars on That '70s Show in 1998, where they played on-again, off-again couple Jackie Burkhart and Michael Kelso, but it would take nearly 15 more years before they started dating off-camera.
After beginning to casually date in 2012, the couple's relationship quickly turned serious, and they moved in together that year.
In February 2014, PEOPLE confirmed that the two were engaged, and shortly after it was announced that Kunis was pregnant with their first child, Wyatt Isabelle Kutcher, who they welcomed on Oct. 1, 2014.
The two tied the knot in a private, low-key ceremony in July 2015 before welcoming their second child, a son Dimitri Portwood Kutcher, in November 2016.
Matt Winkelmeyer/Getty Mila Kunis and Ashton Kutcher
Kutcher spoke to Entertainment Tonight about Kunis encouraging him as he trains for the 2022 New York City Marathon.
"The biggest change physically has been the transfer of muscle mass from upper body to lower body. I've lost about 12 lbs.," he said, adding that Kunis "has been super supportive."
The actor is running the marathon to raise money and awareness for Thorn, which works on technology to defend children from sexual abuse and eliminate child sexual abuse material online — but Kutcher mentioned his family is also a big inspiration to cross the finish line.
"My baseline 'why' comes down to leaving life better than what it was given to me. My daily motivator is my kids and family," he told ET.