The Spectacular Now
Miles Teller and Shailene Woodley both had some issues pulling off their kissing scenes. For starters, Teller hated the way Woodley's herbal supplements made her breath smell. Woodley said that she hated the Gatordate that Teller drank. Obviously, these things were said in jest, and they costars didn't dislike each other, just each other's breath!
Camille
In an interesting twist, Sienna Miller had some hang-ups about kissing James Franco, but for very odd reasons! She's always had issues with her teeth and those problems would flare up from time to time. Unfortunately, the day of filming the kiss, she was having those undisclosed issues. Instead of telling everyone what was happening, she just decided to try and nix the scene altogether.