That
Celebrimbor was in fact in love with
Galadriel (but she did not return his advances) is mentioned in the "Unfinished
Tales", at least in one of the many Galadriel versions.
(There's an interesting discussion about this here:
https://www.quora.com/If-Celebrimbor-loved-Galadriel-why-did-he-and-his-Gwaith-i-Mírdain-rebel-against-her-rule-in-Eregion-and-force-her-to-flee-to-the-East )
But who isn't in love with (book-)Galadriel?
So I agree with you that
Annatar wants to sleep with her, too. Somehow, though (especially after the "Superfans" video 😹 ), I have a feeling by now that Amazon is going to put some LGBTQ+ stuff in there, too - even more so after I saw Amazon's first season of "Wheel of Time". Perhaps
Sauron can also turn into an attractive woman if it helps him with his goals? I'd be surprised if Amazon didn't exploit this option.
When it was announced that Amazon had hired an "intimacy coordinator", the outcry from fans was very loud. Perhaps it wasn't too late then, and the showrunners reacted accordingly: They promised in the Vanity Fair article that there will be no sex scenes like in Game of Thrones.
I'd also say that sex scenes are of course not typical for
Tolkien, but in a modern cinematic/TV adaptation I personally - apparently in contrast to many other fans - would not be particularly bothered too much if it was rather subtle and not tastelessly realized. (But it should be known relationships from the
books, not some made-up fanfiction-nonsense.) These media are there to visualize what is only hinted at in the books, but without distorting the spirit or meaning of the original.
Difficult subject, and I don't have a final opinion on it yet. For me it depends a lot on the quality of the implementation. In practice, however, you can probably almost only do it wrong. Nevertheless, that would be rather unimportant for me in comparison, as long as they manage to tell exciting and atmospheric stories that at least partially bring the experience of the books to the screen.
What I try to say: A small sex scene doesn't necessarily have to destroy the immersion, if the conditions are right. However, after the trailer and the photos and the rights issue and the arrogant statements of the showrunners, I'm almost sure that Amazon will ruin nearly everything - even without any sex scenes.