4th Degree

The Fight Game, Book 5

De: Nikki Castle

Narrado por: Sean Masters, Stella Bloom

He's her coach. She's too young. They're both risking everything.

Forced to grow up too soon, Skylar has built her entire life around taking care of her family. But when she catches her first lucky break, she’s finally able to pick up the sport that has always intrigued her.

Signing up at the local MMA gym is where she meets Coach Dominic. Because everything in Dominic’s life is based on his reputation as a coach and fighter, he’s always kept a professional boundary between himself and his students. But when Skylar impresses him in the gym, and their post-class chats start to last into the night, that boundary begins to blur. Before long, a relationship develops between them—that they’re forced to keep behind closed doors.

While Skylar struggles to balance her feelings for Dominic with taking care of her family, Dominic has to decide if he’s willing to risk everything for a chance at love.

Will Dominic and Skylar let themselves find happiness with each other? Or is the cost of their relationship too high?

4th Degree is the fifth novel in the Fight Game series, but can be listened to as a standalone.

©2024, 2025 Nikki Castle (P)2025 Audio Sorceress and Nikki Castle

Swoon

Love Sean Masters! This was a hot, quick, swoon listen! Had me blushing, crying, and giddy by the end.

COACH!

October 2025 Review (Audio)

Story: 12/10
Spice: 5/5
Spice Hierarchy: spicy
Narration: 5/5, duet

Skylar is looking for something just for herself as a chance to take a break from the demands of her life. Dominic is content with the life he’s built for himself.

Even doing this story the second time, I still love it. Skylar is so strong and Dominic doesn’t ask her to change. But tries to show her ways to find joy and happiness in small things just for herself. I love this found family of Bulldog MMA.

We needed coach to have an authoritative voice while also being the more playful Dominic that Skylar brought out. Sean Masters did exactly that. Skylar needed to sound like the 19 year old she was while brining that piece of maturity that set her apart. Enter Stella Bloom. Both narrators were perfect for their roles.

I don’t want this series to ever end. Especially when Nikki keeps writing incredible stories and selecting phenomenal narrators.

*Original Review (May 2024)
Story: 12/10
Spice: 5/5
Spice Hierarchy: Spicy

Dominic is content running his gym after retiring from MMA fighting. He has his fighters that have become his family and he doesn’t want or need anything else. Enter Skylar. Fighting and the workout it provides is the release and one selfish thing she does for herself. Skylar and her family have not had it easy and she works tirelessly to take care of her family while also going to school full time. They have an immediate attraction, but resist. For awhile at least. But once they start, all bets are off.

We’ve met Coach Dominic in the previous Fight Game series. Color me shocked to find out that Coach was the same age as me (36) not a much older man (50s-60s) that I had been picturing through the previous stories. When he reminds Skylar she is with a man, not a teenager, I was done. He is. A. GROWN. MAN and knows what he wants and uses his dirty words to make * it * happen!

I don’t know what Nikki puts in her drinks, but I will buy her a lifetime supply. Everything she writes is just absolute perfection. That moment from even the chapter headings going from “Coach” to “Dominic” added to the story.

Was I worried about this much of an age-gap? Initially yes. But the story was just so good that it didn’t seem like it was a big gap. While the age difference bothered Dominic to start and he was worried about how he would be perceived, he never wavered in his feelings for Skylar. If anything, he was extra cautious because of the age gap. And Skylar has lived more in her 19 years of life that she was more mature than many her age. Because of their age difference, it allowed Dominic to show Skylar how to find small times and small ways to enjoy her life outside of work, the gym, and her family responsibilities.

I got to 75% and I couldn’t decide if I wanted to abandon all responsibilities and finish or slow down time and just stay in this world forever.

Coach and Skylar!!! 😍😍😍

I didn’t think I could fall more in love with Dominic and Skylar but Stella Bloom and Sean Masters really brought these characters to life!

This audiobook is so good! I know probably say this every time but I seriously don’t know what Nikki puts in her books! I love every single book in this series but I’m sorry to say Coach and Skylar just took the top spot as my favorite in the series! If age gap and forbidden romance is your thing you don’t want to miss out on this book!

Not going to lie this is my first coach/athlete romance but not my first age gap romance, and Nikki has me hooked!! Coach and Skylar were the perfect introduction to this trope if you ask me, which you probably didn’t 😂. The dynamic and build of their relationship was perfection. I loved Skylar’s character so much, she hasn’t had the best life and she has a hard time letting anyone care for her, she’s a hard worker and just overall an inspiration. And Coach! What can I say, he’s hot, and he wants to take care of Skylar but he knows he shouldn’t pursue a relationship with her because she is one of his athletes, but he can only hold out for so long 🤭. And in true Nikki fashion the spice was hot and I just couldn’t get enough of these two, I wanted more at the end!! Let’s also not forget all the cameos from past characters I think that’s my favorite part of this series the gym family dynamic is something I’ve never read before and I’m so here for it!!

I seriously cannot get enough of this series or Nikki Castle’s writing and I can’t wait to see what she brings us next!!

A Teddy Bear Coach and His Brave Fighter

“Every rule I ever made for myself shattered with her.”

This book had me melting and fanning myself in equal measure.

Coach Dom Caruso is a gentle giant—a total teddy bear despite his fighter exterior. I was so touched when one of the gym kids came to him for a recommendation; it showed how much trust and respect he earns outside the cage. His heart is huge, and his love for Skylar sneaks up on him—and us.

Skylar Vega is pure selfless strength. Balancing school while caring for her disabled mom and little brother Joey, she’s been carrying the weight of the world on her young shoulders. Seeing her finally step into the Bulldog MMA gym—and into her own life—was so rewarding.

The spice in this one? WHEW. By far the spiciest in the series.

1.Their first time after Dom kicks out her obnoxious classmate? 🔥
2.The “teach me” scene? I was clutching my invisible pearls.
3. And every moment after? Explosive and tender all at once.

The duet performance by Stella Bloom and Sean Masters brought Skylar and Dom to life perfectly. Sean gave Dom this warm, controlled yet deeply protective tone, and Stella captured Skylar’s mix of determination and vulnerability beautifully. I also noticed the subtle narrative shift—chapters are labeled as “Coach” until after their first time together, when he becomes Dominic. It feels symbolic: the boundary between coach and lover finally blurs into intimacy.

This story was tender, emotional, and scorching. Dom and Skylar’s love feels risky, forbidden, and absolutely worth every second.

📣 Special thank-you again to Nikki Castle and the Facebook giveaway that introduced me to this unforgettable series. I’m so glad I got the chance to experience these characters and their journeys. What a ride!

I love them 😩

“And I’m not worried about what other people think. Because I don’t care about anyone’s opinion who looks at the way I love you and questions why.”

I love this world 🤍 the sense of found family here is unmatched. it’s my favorite piece of this story. Skylar and Dom are the perfect fit for each other, just the right balance. After taking care of everyone else for so long, she needed someone to push her to prioritize herself for once. 🤍

I can’t stress enough how badly everyone needs this entire series in their life. The audiobooks are recorded duet (THE BEST) and the narrators are chosen with such care that they perfectly embody the character they’re representing. The entire series is a yearly reread for me. 🤍

Caretaking + Sacrifices + Age Gap = Swoon

The 5th (final?) book in the fight game series. As with the rest of the series that I've read, this one stands alone well and can be read without any other background in the series. However, if you have read other books in the series, you get to enjoy some more time with the Bulldog MMA family which as a found family lover was a joy for me.

I loved this book. The was Coach Dom and Skylar were so perfect for each other, it made me swoon and melt so hard. Yes we get some age gap with forbidden/taboo qualities here (Skylar is 19, Dom is mid 30s and her coach), but we also get a caretaking hero who sees the hardworking, self-sacrificing heroine and just wants to make her smile. It's the sweetest thing ever!!

As mentioned, there is the Coach/Trainee aspect here that causes the relationship to start on the down-low. It's innocent enough at first as they both fight their feels and desires, but still have that unmistakable urge to stay within each other's orbit. But once the slow burn stops simmering... there is no stopping these two (even if they did want to try). And though we have a conflict in the 3rd act, it's external in nature and we still get a grand moment.

The audiobook was performed in duet style by Stella Bloom and Sean Masters. The voices for this pairing were so perfectly cast. Stella brings such a softness to her tone that makes me believe the college aged girl with the weight of the world on her shoulders. The emotional journey for Skylar from hopeful to guilt, frustration and sadness when circumstances beyond her control change, the pride and reluctance to ask for or accept help. When her walls come down, my heart went squish. Sean's smooth buttery voice as Dom was a perfect harmonic match to Stella's Skylar. I could hear and believe the age gap. World weary, slightly grumpy, but also so aware of Skylar at all times in multiple ways. The inner battle for Dom in his interactions with her transitioning from "Coach" to "Dom", even the urge to keep her near be it extra training, helping with cleaning or just watching TV together, the way this man battled within himself about his need for her well-being. And then the side characters in this found family of a gym team. So exceptionally good that I got all teary when we get to the climax/resolution of the conflict.

I requested and was provided an advanced copy of the audiobook. These are my honest opinions.

My favorite!!

Added Audio Review🎧
Coach and Skylar have finally joined the rest of the crew on audio and they do not disappoint. These two are fun, emotional, spicy and loving. You get Coach in his gym setting but then you see the side he hides from everyone but something about Skylar has him opening up and showing all of him. Skylar has world on her shoulders and pushes everyone away but has a soft spot for Dom and lets her walls down. They are so sweet together, I love their chemistry.

Sean Masters and Stella Bloom did an amazing job and made me love this story even more!

“Take the Hall of Fame Award, take my career, take my 4th Degree black belt, I don’t care. She’s worth it all.”

4.5⭐️ Nikki truly has a way with words and getting you sucked into her story from the start. If you have read this series before you know the “found family” trope is one that is ever present and this book absolutely delivers. It is one of my absolute favorite things about this group. The way they all of their struggles but are so accepting, love each other so hard and always have eachother’s backs! Coach Dominic is a dream. He is stuck in the same routine and not realizing how lonely it can be until Skylar enters his gym. Skylar is selfless and due to personal tragedies in her life that has caused her to grow up at such a young age she doesn’t have time to do things for herself. She takes a step out of her comfort zone and joins the gym because it is something she has always wanted to try. These two are instantly attracted to each other and they know they shouldn’t be together but the tension sure makes it hard for them to resist. The age gap was done so well in this story. I honestly found myself forgetting how young Skylar is because of how mature she is and the way these two just fit so well together. Their relationship flowed so well in the story. The way Dom took care of Skylar and pushed her out of her comfort zone had me swooning but then his dirty mouth will have you fanning yourself because the spice is so good! Loved all the appearances from past characters and having them together again with little glimpses at where they are now. Forever loving this series!

Age gap, sports romance (MMA), coach x athlete! Obsessed!

4th Degree is the 5th book in the Fight Game series! The whole series is amazing by the way! Anyways, this is a forbidden, coach/athlete, age gap, sports romance (MMA) with found family and “teach me” moments!

Skylar has been juggling a lot: shes 19 and in college, she takes care of her mother who has early onset Parkinson’s, she’s looking after her younger brother in highschool, she works a job and pays the bills for their household and her mom’s medical care! She wants something for her and has always been into watching MMA fights and decides to start taking lessons at a local gym. She meets Coach Dominic there on her first day, he’s not only the owner and head trainer of the gym but a former MMA fighter too. They start spending more time together at the gym and end up bonding over watching and talking fights. Both start feeling pulled to one another but have reasons of why they shouldn’t get involved too!

I loved these two together. It is an age gap romance (she’s 19, he’s 36). They were honestly perfect together and the chemistry and connection was so good! I loved how they try to keep their distance at first but eventually give in and can’t stay away. Her surprise of him wanting to actually hang out with her after and still watch fights together was so cute! I love how he wants to take care of her and wants her to take a break for a day or have something for herself. Her brother was so cute in the story too and I just loved the whole found family vibe of it all. I love this whole series so much and this one was such a sweet addition!

soulmates

💚 coach x student
💚 age gap
💚 secret relationship
💚 dorbidden
💚 found family

Dom "Coach" has resigned to making his gym (and dog) his life, maintaining a strictly professional relationship with a member of his gym. That is until Skylar walks in. There's an instant connection and sunshine she exudes whenever she is around. Dom keeps his distance until Skylar makes the first move.

Dom and Skylar are the epitome of soulmates.

Narrated in duet by the amazing Sean Masters & Stella Bloom.

4th Degree - Nikki Castle

⭐️⭐️⭐️⭐️🌶️🌶️🌶️ I swear, these books are even better in audio! I read this back in 2024 &enjoyed it but the audio was amazing!

* The narrators crushed it! I’ve loved Stella Bloom for a long time but Sean Masters is relatively new to me &he didn’t disappoint! Him saying baby 🫠🫠🫠. Both narrators did great bringing the characters to life!

* Nikki Castle’s writing style is great! I could vividly picture the gym, the tournament, Coach’s place, the dynamic of Skylar &her family. It’s truly amazing storytelling.

* Skylar being the overachiever &responsible one was definitely relatable. Having to take care of her mom &trying to keep her brother young was admirable. Also, most age gaps make the young one seem so immature to exaggerate the age gap but this one didn’t do that &I loved that!

* Coach was so well respected at his gym &in the community, it was hard not to fall in love with him. Which was what made all his interactions with the other fighters so touching. You could see the true family he had with all of them at the gym. I loved how they all embraced Skylar into their crew.

* The spice “yes sir, yes coach” was 🥵. The mat scene will live rent free in my head indefinitely. Along with the first time at Coach’s place.

* I highly recommend this book &the entire series!!

𝐓𝐡𝐞𝐦𝐞𝐬:
* Found family
* MMA romance
* Coach/student
* Age gap (17 years)
* Forbidden romance

𝐃𝐞𝐭𝐚𝐢𝐥𝐬:
* 19 year old Skylar Vega joins a gym to do something for herself. She walks into Bulldog MMA, a local gym owned by 36 year old Coach Dominic Caruso. Skylar ends up staying later each night &having more contact with Coach. They both know they shouldn’t cross this invisible line, but will they listen?

* This is book 5 in The Fight Game Series.