Tarzan and His Mate - Tarzan e la compagna (1934)

There is also some partial (and not so partial) nudity. The eroticism in this movie (I do think the movie is erotically charged) is derived not so much from the lack of clothing but by the contrast between the fully-clothed 'civilised' Harry Holt (Neil Hamilton) and Martin Arlington (Paul Cavanagh) and the loincloth-clad Tarzan and Jane. Holt tries to seduce Jane by offering her gifts such as clothes (interestingly including underwear) and perfume, to which she has no longer access since she's lived in the jungle with Tarzan.
Another element that adds to the eroticism in the movie resides in its action; all physical activity by its protagonists seems to hint at a very active sex life between them. Their youth, strength, and beauty plus their defiance to common Western rules of behaviour (including their already mentioned shedding of clothes) make both Tarzan and Jane sexual rebels. We may not see them having intercourse (even in Pre-Code days that was unthinkable) but we see them doing a lot of running and swinging from trees. They clearly love each other: Jane does not succumb to, nor is she even tempted by, Holt advances; and Tarzan risks his life to save her. Their love is intensely passionate and we know they do not spend much time talking (Tarzan barely mumbles a few phrases although 'I love you' to Jane is one of them).

A year after the events in Tarzan the Ape Man, Harry Holt (Paul Cavanagh) returns to Africa in search of ivory. Holt also hopes to lure Jane away from life with Tarzan with a selection of evening gowns, shoes and make-up — the trappings of civilised life. Holt and his sidekick deal with their crisis of masculinity with wisecracks and cigars, while the scarcely clad Tarzan and Jane swing through the trees playing erotically charged games and evading wild animals. Jane narrates their activities with references to English high society rituals — mocking her ‘civilised’ past (and its men), and championing her life with Tarzan in their jungle paradise.