Les vignes du Seigneur

Henri, a reformed alcoholic, is engaged to young Yvonne but is in love with Gisèle, her sister and fiancée of his friend Hubert. They all go away on holidays together to a villa owned by Valentine Bourjeon (the sister's mother). There, Henri and Gisèle have an affair. Despite their many precautions, they are quickly found out by everyone except Hubert who hasn't noticed a thing. But Mrs Bourjeon sets her daughters' love lives straight.