TheSymphony: Is that a correct understanding? Can I play the whole game and avoid all of the nudity/sexual content? Or is it forcibly part of the storyline at some point? And, if it is part of the main storyline, is the scene skipable?
I've played some time ago, so I'm not giving you a 100% guarantee on this list being complete, but so far as I remember:
1. The "bath wenches" (as the game would call them) are fully optional - it's a dialogue option you never have to click. You can safely visit the bathouse for normal things like a bath, hairstyle change, etc. without any sex scenes.
2. A few side questlines with female NPCs have a romance undertone. It's possible they could end in some sort of skippable romance scene. I would be surprised if it were actual nudity, though. I say this as a hypothetical because the one time I actually ended such a questline I chose the "clean" option of not pushing for romance (it felt out of place to have the protagonist do anything with the lady of a castle).
3. One side quest involving Hans Capuon is suggestive, since he is a known womanizer and asks you to meet him at the baths. Just don't take / complete his quest. Not sure about the DLC named after him - that might some more content of that sort but would obviously be skippable by not engaging with the DLC content.
4. One main quest has two paths to completion, one of which involves getting horribly drunk and the protagonist waking up witnessing a sex act. It's a skippable scene but it's also a skippable path - if you choose to play a prim and proper person, you can refuse to drink, which avoids the general debauchery (you'll just have to get a piece of information through other means).
5. If you are, perhaps, concerned about other sorts of improprieties, there's a side quest where the protagonist is asked to stop a bunch of women who are trying to participate in ""witchcraft" - no nudity but the quest involves the protagonist being mistaken for The Devil. Thought I'd throw that in in case that sort of thing would bother you.
Overall, everything on this list is optional, with different ways to avoid it. The side quest content that's suggestive will clearly stand out as such, while the main quest part can be avoided by playing a Henry who's not into impropriety.