I watched a movie about 15 years ago and I am trying to find it again.

It was set in the 1950s. Two teenagers (neighbours?) fall in love. There is a pretty steamy scene in a swimming pool. They are different religions (Catholic and Protestant, maybe?) and their parents forbid them from seeing each other. The girl's family moves away.

At the end of the movie, the boy has grown up and is an author signing books in a bookstore and he sees her with her son, who is named after him.

Any help would be greatly appreciated!