Mum's the Word.

A widow has married rich, but didn't tell her husband about her son. And he's coming for a surprise visit. To hide his identity he is introduced as the husband's new valet, but still the husband has some doubts about a few strange scenes. And during the night, when the son tries to visit his mother, the husband always starts interfering, but the new maid also behaves strangely, trying to sneak into the husband's room...