Portman co-starred with Kutcher in 2011's No Strings Attached, and also shared the big screen with Kunis in Black Swan a year prior. Both roles required some hot and heavy make-out scenes, something Portman readily pointed out during the show's "Dish On A Star" segment.
"I've kissed them both," she bragged.
Cohen jumped right in, asking Portman, "Who's the better kisser?"
"Mila!" Portman exclaimed without pause. "I mean, obviously."
It seems Kunis is a fan of Portman's kissing too! In a Reddit AMA back in 2015, Kunis said that Portman is "a lovely kisser, very polite."