Actor Philippe Martin (Francis Lederer) and his married date Yvonne (Liev De Maigret) plan to neck in a darkened cinema, but he gets the wrong seat and mistakenly kisses lovely Monique (Ida Lupino), a publisher's daughter. An absurd scandal results; to protect Yvonne, Philippe insists that he was simply overcome by Monique's beauty. This naturally intrigues Monique...but her nominal fiancée (Erik Rhodes) feels differently. French bureaucracy is broadly satirized.
You can stream One Rainy Afternoon (1936) free and legally on alltube, via the Internet Archive.
Yes — it is in the public domain and can be watched and shared freely.