While the movie draws upon the Peter Bogdanovich / Cybill Shepherd / Polly Platt love triangle for its inspiration, as many critics including Roger Ebert have noted, it also draws upon Nora Ephron's "Heartburn" for much of its inspiration, as Platt never wrote a bestselling novel about her husband's affair, but Ephron did.
Ryan O'Neal took the role for no salary, just points, because he really wanted to do it, but they didn't have the money to pay the actors what they usually earned. He said he loved the movie and thinks it's some of his best work.
The expensive flop musical that the Ryan O'Neal's character makes as a vehicle for Sharon Stone's character is a thinly veiled reference to At Long Last Love (1975), the expensive flop musical that Peter Bogdanovich made as a vehicle for Cybill Shepherd.