"the only thing we have to fear is fear itself" -Franklin Roosevelt
Fear of failure
Fear of abandonment
Fear of challenge
Fear of jealousy
Fear of hurting another
Fear of pain
Fear of the unknown
Fear of regret
Fearing the leap. Fear of the bad that could rise from potential good. Fear one day she wouldnt take him back. or worse: that he would even if she'd hurt him.
Fear one day she'll be defenceless against his charm. That one day she'll care more about him, than he, her.
Perhaps its fear of comfortability, of letting their guards down completely.