I love everything Nikki Castle writes, and I really loved <i>4th Degree</i>. This is a forbidden, coach/athlete, age gap, sports romance (MMA) with found family and “teach me” moments! Dominic and Skylar were the perfect pairing, despite the gap of almost twenty years (she's 19 and he is 36). Skylar was definitely wise beyond her years and so mature, especially because she was the caretaker of her mother who suffers from Parkinson's and her teenage brother. I really loved how strong and resilient she was, and how she eventually learned that accepting help is okay, especially from those that love and care for her. Dominic and everyone else at the gym really wanted to help Skylar and it was interesting to see her blossom from just going to the gym for self-care to part of the family. I loved the forbidden aspect of this and I do think it was really well done, despite her being under 21 and him being in a position of power over her. It wasn't creepy or feeling like it was him taking advantage of her (in fact, this is plot point later on) and I enjoyed their dynamic and how clearly they were made for each other, despite very big differences. I really enjoyed this book and I hope there are more in this series!