Flossie (1974)

This movie is loosely based on a Victorian novel by the same name. Here’s a description of that book:
FLOSSIE, sometimes attributed to the poet Algernon Charles Swinburne (though without the slightest evidence for the claim) is the “Deep Throat” of the Victorian era. It is briefer and less floridly written than most Victorian erotica. It has the virtue, rare in these novels, of coming directly to the point. Captain Archer, the narrator of the novel, is an experienced man of thirty-five when he meets fifteen-year-old Flossie while strolling in Piccadilly. He is immediately struck by the size of her breasts, and is happy when he receives a note from her guardian. Miss Eva Letchford, encouraging him to become Flossie’s companion because the girl has fallen in love with him. But Flossie has promised Miss Letchford that her hymen will remain intact. Sexual activity will have to be limited to fellatio and cunnilingus –“gamahuching” as the Victorians called oral sex–but as Flossie and Captain Archer practice them, these activities are never limited. Flossie is notable for its concentration on oral-genital activities, and its heroine’s youth, as well as its direct, uncluttered language.