United Kingdom, Dec. 17 -- Keira Knightley will eat "something disgusting" to give herself bad breath if she has to kiss co-star she "hates".

The Pirates of the Caribbean star, 40, has opened up about her "etiquette" for onscreen smooches and admitted she tries to make sure she smells "minty fresh" for romantic moments on camera unless she's paired up with someone she doesn't like - joking she would scoff "as much garlic as possible".

During an appearance on the Dish by Waitrose podcast, she explained: "Oh yeah, yeah, yeah, there's etiquette.

"If you really hate somebody obviously then you have something disgusting and like you smell. But if you really someone obviously there's chewing gum, you need to be minty fresh.

"No, that's unsp...