Sometimes a little love and support can go a long way, especially when you're walking the red carpet at the premiere of your new film.
"I think I'll just keep it simple and say break a leg, and I know it's going to be amazing," Kutcher said in the video recorded by ET earlier that day. "You have nothing to be nervous about, and you look stunning."
Kunis, who watched the message on the red carpet via tablet, gushed after hearing Kutcher's sweet sentiments.
"I mean, how do you not love him, right?" The 31-year-old actress asked, smiling broadly.
Kunis and Kutcher, who played high-school sweethearts on the Fox sitcom That '70s Show, began dating in April 2012, and got engaged in February 2014. The couple welcomed their baby daughter, Wyatt Isabelle, in October.
Check out the video for more from Kunis, including what Kutcher's "daddy duty" was the night of her big premiere.