It's pretty much impossible to brighten a scene like that, there's basically no light source projecting on that area. Maybe if you ask the studio for the raw footage you could maybe catch a glimpse of something with some major tweaking, but you'd mostly get noise and artifacts as you cannot create light that doesn't exist.
With the direct Blu-Ray footage you could probably get a decent look at that woman's pussy though.
That's the best I could do with the terrible streams I found, plus image compression:
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