The April Fools (1969)

Newly-promoted if none too happily married Howard Brubaker leaves a rowdy company party early with the stunning Catherine, whom it turns out is herself unhappily married — to the boss. They spend an innocent night in New York becoming more and more attracted to each other, so that when Catherine announces she intends to leave her husband and return to Paris, Howard asks to go along too.

Directed by: Stuart Rosenberg

Starring: Jack Lemmon, Catherine Deneuve, Peter Lawford, Jack Weston, Myrna Loy, Charles Boyer

Links: IMDb, Movie posters, Movie stills