No more to go

I've been reading this series on and off for a while and just recently binged on the last two and it reminded me of the best of romance, the meeting of two people who at first seem incompatible but turn out to bring out the best in each other and find that they miss having the other around, no matter how much the other infuriates them sometimes.
Wulfric Bedwyn agrees to go to a house party and Christine Derrick agrees to go too, they're not a couple, in fact she is not suitable Duchess material at all. But he can't stop looking at her, being attracted to her and occasionally rescuing her from her good-hearted impulses. She was happily married until her husband started to doubt her, now she lives in poverty and tries to be insignificant. Then Wulfric asks Christine to be his mistress and she refuses.
He wants her in his life but he's not sure that she's a suitable wife. Can he survive without her?
Charming and entertaining and worth reading.