Tonton Streaming Upstairs, Downstairs (1971) S1E12 - The Key of the Door

Winter 1908: Elizabeth befriends a bunch of Bohemian-types, but is drawn to two in particular: Evelyn Larkin, a radical Socialist extremist, and her lover, Lawrence Kirbridge, a handsome, free-spirited poet. On the eve of her 21st birthday, with her parents out of town, Lizzie invites the entire group to Eaton Place, and is humiliated when the Bellamys return home unexpectedly and throw everyone out. Anxious to prove she's nothing like her parents, Lizzie is compelled to do something extreme, leading to a falling out with her parents and a harsh discovery about Evelyn.