The House of Arden by Edith Nesbit

The films were quite dry by bedtime, when, after a delightful evening with no magic in it at all but the magic of undisturbed jolliness, Edred slipped away, unpinned them and hid them in Elfrida's corner drawer, which he rightly judged to be a cleaner resting-place for them than his own was likely to be. So there the precious films lay between Elfrida's best lace collar and the handkerchief-case with three fat buttercups embroidered on it that Aunt Edith had given her at Christmas. And Edred went back to the parlour for one last game of Proverbs before bed. As he took up his cards he thought how strange it was that he, who had been imprisoned in the Tower and had talked with Sir Walter Raleigh, should be sitting there quietly playing Proverbs with his aunt and his sister, just like any other little boy.

"Aha! " said Edred to himself, "I am living a double life, that's what I'm doing."