Serendipity (2001)

On a bustling shopping day in the winter of 1990, Jonathon Trager meets Sara Thomas. Two strangers amid the masses in NYC, their paths collide in the mad holiday rush as they fall victim to a mutual attraction. Despite the fact that each is involved in another relationship, Jonathon and Sara spend the evening wandering Manhattan. But when the night reaches it's inevitable end, the two are forced into determining some kind of next step. When the smitten Jonathon suggests an exchange of phone numbers, Sara balks and proposes an idea that will allow fate to take control of their future. If they are meant to be together, she tells him, they will find their way back into one another's life.