[Kaderin Triste]

Yeah that's what it was!
I mean, lots of sex in an attempt to conceive an heir is at least a plausible reason for excessive smut. It's pretty simple and not really that imaginative, but at least it's kind of a good excuse?

I do like the Kushiel's Dart series by Jacqueline Carey because, while there is some light smut/sex (frequently with decently written s&m), it also has a lot of conflict and political intrigue and an actual plot. I've only gotten through the first 2 books though just because I keep forgetting to look for the next one when I'm at a book store.