Oh. How about The Valley of the Dolls? I’ve never read it, but I’ve heard it was hot.
Oh! Lady Chatterly’s Lover. Never read it, but I’ve heard it was hot.
Clan of the Cave Bear series. I liked the first book best because it had a lot of pseudo science in it. The following books were still readable, but they devolved great deal into Ayla and Jondolar and their hots for each other. She tried very hard not to use the same descriptions twice, which is to say she was very creative. Hilariously so, in many cases. Stephen King once said described it, “Ms. Aule’s randy cave people”
War & Peace has a scene where he slams her up a door. Or wait….was that The Godfather? I forget. You’ve seen one smut, you’ve seen them all.