In a word: getting lipstick everywhere during those kissing scenes. "It's not really the smudging that I worry about — women are good about being aware of that — but it's how it transfers onto the other person's face," said Modica. "Either way, it's almost impossible to prevent. I always use a matte lipstick or stain, or just lip liner on its own, to keep it in place. It's the bane of my existence."