See...it makes no sense to me that she would hide it out of fear he'd go back to the priesthood. The man just resigned from it without knowing the board's decision, and told her he loves her and wants to be with her.
If she really wants to have him prove she's not 2nd best, show him the diary and notes and see what he does. I seriously thought that after all this time, Nicole of all people should know what love is and is not, and that no good whatsoever comes from keeping a secret in that town. If she wants it to be real, she shouldn't have a qualm about telling him. By not doing so, is she not settling for second best, wondering what he'd have done if she'd been honest, and worrying for the rest of her life that he would find out and wondering what he'd do then?? The never ending story of Nicole?
For the love of all things holy...she can't be stupid enough to do something like this again. I have to believe there's another reason. I don't want to see Nicole hiding the truth out of fear she'll lose a love that she doesn't even really (apparently, if this is how the story is going to play out) know for sure is real...AGAIN.