Misty (currently airing) somewhat fits. The leads are married, although the FL was clear with the ML when he asked her to marry him that she did not love him. At the beginning of the story we see that the FL is having fantasies / flashbacks of her ex. The ex then comes back into her life. She dumped him pretty coldly because he lacked prospects, and he's spent years building himself up so he can make her regret her words. The ex is very forward with her and eventually forces himself on her so he can get compromising pictures of them kissing, and later on the FL is recorded while trying to appease him (she lets him kiss her) after he tries to use the pictures and their history to blackmail her. The ML learns of their history and sees the recording, but decides to stay with her. Through the events that follow, the FL starts to fall for her husband for the first time. Not sure how it all ends yet since there are two episodes left.