I stayed with someone who fits her description except she was very into sex and passionate but I never truly felt a strong enough chemistry for some reason - as you said "a bit of a chore" similar feeling.
I stayed with her as my heart wandered frequently for 8 years (3 engaged) I had many opportunities of course I didn't engage in, several would have been very interesting for sure, but I couldn't cheat on the sweet vanilla girl.
Sadly after 8 years she wanted more, at that point I was resigned to staying with her, long story we broke up, it was sad and tough, but she's doing great now and has a husband and kid, I'm single and bleh whatever so, lesson is, I should have ended it the first year after a couple of honeymoon months - we'd all have saved some years and been better off.