Book recommendations where both the man and the women are morally grey.

I’m looking for some book recommendations where both the man and the women are morally grey. (mainly just not nice people in general) I’ve been getting bored of the books where it’s all sunshine and rainbows.
In most the books i’ve read normally it’s just the man that’s morally grey but i want them both to be. It would be great if it was a slow burn as-well but if it’s not that’s fine.