Bound to the Past (Stronghold #7)
Golden Angel

Now he wants to make things right and put the past behind him, but in order to do that he needs closure and Kate's the only one who can give it to him. Of course, once they start spending more time together in the present, it starts to become clear that maybe he's not quite as ready to put their past away entirely.
Ever since her return to Maryland, Kate hasn't been sure how to feel about her ex-boyfriend. She hated who he became while she was gone, but she can see him starting to change again and she likes the man that he's become over the past few months. He's different, but the same, and when she agrees to scene with him again, she decides she's not going to close herself off to the possibility of reconciliation.
However, the incident that shattered their past is now threatening their future together, making it harder for them to move forward from where they were. They have to decide whether or not they're going to try get their happily-ever-after, and if so, they're going to have to do what they didn't do before and fight for each other.
This is part of the Stronghold series and can be read on its own, although is more satisfying when read as part of the series. The book is approximately 87k words and includes BDSM, whipping, spanking, kinky sex, alpha males, and a guaranteed happily-ever-after.