Iirc, most of the Stephen King stories made into movies aren't highly sexed. They left the sex-oriented story line out of "IT" for example, but if you read the book you realize the kids did some pretty adult 'experimenting' the first time It showed up. "Rose Red" alludes to masturbation once that I remember, but other than a little rough language, I don't recall anybody getting naked, etc.
My first horror movie was "Silence of the Lambs", but I'm not sure how you feel about the cross-dressing in dead womens' skins part of it. I don't recall any nude scenes though.