Megan Fox "almost cried" when food from an actor's mouth passed into hers during a kissing scene.
The 'Transformers: Revenge Of The Fallen' actress hates locking lips with co-stars and is especially scathing about one man who didn't brush his teeth before filming their love scene.
She explained: "Oh my God! Screen kissing is f***ing gross. It's a super intimate thing to do. Touching mouths? I have to really enjoy someone's personality, not just their looks, before I'll kiss them.
"This one kid I had to kiss had just eaten. And he passed a piece of whatever it was into my mouth. I swear to God. Not on purpose. Like it was in his tooth or something? And it was really salty. I almost cried. I was a b***h the rest of the day."
The 23-year-old actress wanted to be famous from a young age, but admits life in the spotlight is not as perfect as she hoped it would be.
She told Britain's GQ magazine: "I grew up craving the spotlight and once it happened I immediately recoiled. It just always seemed really glamorous. As a child you think everyone who's famous is very wealthy and powerful. I thought my internal issues would be solved and I would be this really confident person. And I'm not."