It is subtly implied an unmarried woman spends a weekend away with a man.

A older upper-class woman falls in love with her gardener, to the disgust of her the middle class family and friends.

Some kissing here and there.

None, unless two uses of "darn" ruffles your feathers.

A few characters drink at a few points in the film (social drinking). Cigars and cigarettes are seen, not really smoked.