A Lot Like Love (2005)

While flying from Los Angeles to New York, the "good boy" Oliver Martin (Ashton Kutcher) meets the "bad girl" Emily Friehl (Amanda Peet) and they have sex in the restroom. They stay together along the day in New York, when Oliver discloses the planning of his life - his future career, successful job and then raising a family. He gives the phone number of his mother to Emily and asks her to call seven years later to check. For seven years, they occasionally meet each other, and in the end, their relationship becomes love. [imdb]