Matt Damonis opening up about kissingScarlett Johanssononscreen — and it didn’t quite go the way one might expect!

“We went to lunch and she and I both thought [filming the kissing scene] was over and she ate, like, an onion sandwich,” Damon told Blunt, 40. “And she came in and [director]Cameron Crowehad set the camera up and it was, like, a tight shot of the kiss.”

“And she goes ‘Aw s—! I literally just had – I had, like, an onion sandwich,’ " he said, laughing.

The conversation, which was about whether you should tell someone they have bad breath or keep mum, began when Damon said he “hadto kiss Scarlett Johansson” for the movie.

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Scarlett Johansson and Matt Damon at the premiere ofWe Bought a Zooon Dec. 12, 2011, in New York City.Dave Allocca/Starpix/Shutterstock

Scarlett Johansson and Matt Damon ‘We Bought A Zoo’ film premiere

Dave Allocca/Starpix/Shutterstock

“Can you imagine how horrible that was for me?” he joked.

“It’s such a shame — shehas such terrible lips,” Blunt quipped. “Must’ve beensoawful.”

“It was hell,” he joked in addition.

After Damon shared the story about the onion sandwich, Blunt playfully pressed him, “But were you still sort of slightly aroused getting to [kiss her]?”

In the end, “I was making fun of her the entire time about her onion breath, which I didn’t even smell,” Damon replied, adding with another laugh, " ‘Cause her breath smells like roses.”

Scarlett Johansson and Matt Damon inWe Bought a Zoo(2011).Twentieth Century Fox Film/Kobal/Shutterstock

Scarlett Johansson, Matt Damon We Bought A Zoo - 2011

Twentieth Century Fox Film/Kobal/Shutterstock

Damon’s onion-laden kiss with Johansson was just one anecdote from the set ofWe Bought a Zoo, in which the actors played a pair who connect after Damon’s widower character acquires a new home with his children that also includes a zoo on the property. (Johansson plays a zookeeper whom Damon’s character develops a relationship with.)

“He was definitely sweating a bit, and maybe the sweat formed in the corner of his eye," she added. “I said, ‘Matt, these kids are practically juggling the snakes. Hold it together.’ ”

Oppenheimeris in theaters now.

source: people.com