Continuity mistake: New Year's Eve dinner scene, Rob Lowe's salad plate has one tomato slice on it. The next shot has the tomato slice gone from the plate, and in the next shot, the tomato is back on the plate.
Continuity mistake: At the bar on St.Patrick's Day, Rob Lowe comes in and his hair, face, and coat are soaking wet. When he follows Demi outside, before he goes back out into the rain again, he's completely dry.
The original title of this film was 'Sexual Perversity in Chicago' (taken rom the play it is based on). The title was changed after many newspapers and TV stations refused to run ads for a film with such a title.