In the brothel scenes I experienced a woman attracted to Illithid telling a story about feeling empowered. The two others in the Caress made an offer, but Lae’zel made it perfectly clear that she would not share, so I declined. And there was a clothed dancer and music. That was it.
And I also think that the sensual parts are too absent in Act 3. For Lae’zel you actually get some great relationship parts ("Source of my ..." ← rest left out to avoid spoilers, if you played it, you know), but there is no progression in *shared* sensual experiences.
On the other hand, Act 3 is where the established connections hold fast to drive the main plot and shape decisions (and yes, if you allow yourself to get immersed in what those relationships mean for your character, then they are the major driver of decisions), so dialing them down a bit is consistent with the progression of the story.
