Hmm…great discussion! Well, as the bible said, desires of the heart belong to man but the desires of the mind belong to God.
So, this says that yes, it is a choice (if it is an emotion of love that determines the decision.) But if you use your logic and rationale to bring you to a point, and loving this person is icing on the cake, maybe then it is destiny and the bonus is you get to fall in-love.