Warren Beatty personally lobbied Katharine Hepburn to come out of retirement and appear in this film. Though he personally rented a house for her in Los Angeles and had her referred to a special dermatologist, she wouldn't give a definitive answer until the day of filming.
Watch "An Affair to Remember" then "Love Affair" back to back. Remember the positioning of Deborah Kerr's hand as she sits on the sofa at the end of the movie. Then watch Benning's hand, she copies Kerr perfectly. She had to have studied and duplicated what is so perfect.
The closing credits list 80's icon pop singer Taylor Dayne as Marissa. While Dayne does have a small speaking part in the movie, her character name is never mentioned. This suggests a scene or more with her were edited from the final cut of the movie.