Agora

Rachel Weisz stars as Hypatia of Alexandria in the film Agora. But despite the movie placing her at the famous Library of Alexandria (in Egypt, which was then under the control of the Eastern Roman Empire), according to historical accounts, Hypatia never actually taught at the library, which no longer existed in her lifetime.

But the only reason I'm mentioning this movie here (and Agora is still very good) is that there's a scene where Hypatia is teaching in her bare feet.

While I'm not sure if this is historically accurate, who cares? It's a very nice, if brief, BF scene with Rachel. She usually wears sandals throughout the film.

Agora was directed by Alejandro Amenábar, who also gave us a great BF bondage scene in Open Your Eyes.