The Handmaiden features several sex scenes between its two women protagonists, Hideko and Sook-Hee. These move the plot along, serve to characterise the two women and their relationship and fit into the generally very stylized, cinematic optics of the film (look for symmetries in the different acts). Definitely more than "fanservice" for people who like to look at improbably beautiful (and thin) women having sex. However, the scenes also made me wonder:
In one scene, Hideko and Sook-Hee engage in tribadism, according to the linked wiki article there's a serious discussion whether this form of intimacy is at all common outside of films (maybe it looks better on film than it feels in the sheets?). The final scene has Hideko and Sook-Hee inserting bells into each other's vaginas in a romantic and, again, highly stylized, scene. Earlier in the film we see Hideko read an erotic story (I think in-universe written by a man, though I'm not sure it's mentioned with this story) that features this act.
I'm very sure the sex scenes are not meant to be realistic or authentic:
Nothing about the movie is particularly realistic, why should the sex scenes be?
The final scene could be understood this way, Sook-Hee and Hideko excape "their" men but they don't escape their male, pornographic vision of sexuality.
I want to double check my suspicion that the sex scenes depict more cinematic or male perspectives on lesbian sex than actual lived experience of women who have sex with women. Did reviewers with closer knowledge of lesbian intimacy comment on "authenticity" of the sex scenes, and is there something like a consensus regarding said "authenticity"?