 If you liked
Kuro to Kin no Akanai Kagi.
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 ...then you might like
Kuzu no Honkai
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Both are examples of on screen sexual intimacy involving unhealthy relationships that is not grossly exaggerated (physically at least).
The MC in both are girls with brother complexes, and the story revolves around the drama this leads to.
Whilst Kuzu no Honkai is longer, with more character exploration, it doesn't distract from the vacuity; if you are after a similar show in terms of cheap softcore pornservice/artistic sexual intimacy (depending on how you look at it), this is the show to go for.