It is not the first time I've read Kate Pearce's work and some of her works I really enjoy, this one has some issues I was having trouble with but overall there were good moments.
Kate Pearce is amazing at writing sex scenes and even though it took 10 years to have my life put together, let me tell you that it is an absolute joy to find these novels with BDSM in a world where erotica in general seems to be forgotten. We could consider it a "trend", but bondage is not a fashion and I still enjoy reading this type of erotica although now it has become harder to find mainstream novels of it.

My main issue relates to the romance aspect: I did not buy it. Whenever I was reading the less intense scenes, I did not buy that the love interest were falling for each other. I would have enjoyed more scenes where their relationship truly developed over the plot, than what happened. I usually feel that with "mysterious" characters the author comes to a point in the novel where they fully display the character but I did not feel that with Diana. She did not need to be that mysterious with a lot of things and I felt that part of her character was never developed. And I felt sad because there was so much potential there: a female dom, who cares for a man and helps him through his journey of self-discovery. I felt we were supposed to board the "romance" train, but we never got there.

Alistair had a longer journey and perhaps the duality of him being a man and a respected one vs. him not knowing his boundaries was more interesting. You could read into his actions and words that he was conflicted between being a family-honored man and not knowing when to say "no".

I would recommend Mastering a Sinner to someone who enjoys more hardcore bdsm erotica and who wants to read more different sex scenes - it is great in that, however, it is not a very romantic novel. If you enjoy Marquis de Sade, you will love this. I have truly missed reading erotica that is not afraid to go there.