I know that you can't really use one of my two fears, but still here goes.
A) Failing (although I've become quite efficient at concealing my emotions on such a matter).
B) Being alone. Like frienless, loveless.
Actually, neither really could be used in a movie, they are both kinda' boring.
EDIT: Typed that then read other peoples. Seems I'm not alone, atleast on part A) of my fears.
That being said, I'm kinda' suprised that in a group of stereotypical perverse and distorted mofo wannabe movie guys, no one has a strange fear. Seems to just be typical stuff. Bugs, ninjas... whatever.
No one has fears of like... oral sex?
lol
"Your girlfriend will find someone better. You will become homeless. And you know whats worse...? You will still suck at Tekken."