7th Heaven

Chico (Charles Farrell) is a poor Parisian sewer cleaner who aspires to work his way out of his dead-end job and into the middle class. When he meets Diane (Janet Gaynor), an abused prostitute, he sympathizes with her plight and tells the police she's his wife to prevent them from arresting her. To keep up the appearances of marriage, he invites Diane to live with him, and a real romance blossoms until Chico is drafted in the army at the start of World War I.