The blurb for your story so reminded me of an old black and white film:
The girl uses details from her father's files to pretend she is very experienced ( though she is really a virgin). Most of the film is her keeping him interested, jellous, and unsatisfied. Her Dad figures it out and has a private word with him. He decides she is too innocent, she pretends she isn't heartbroken, but it turns out that he can't bear to leave her. Teary scene at the train station.
..... I am looking forward to seeing how you handled a similar setup.