Bel's Bewildering Assistant: Underworld Mates

by Athena Steller

Genres: M M Romance, Paranormal

267 pages, Kindle Edition

Published February 26, 2026

Reviews

[Mandy (MP Book Reviews) · Rating 3 out of 5]

Demon Bel’s life changes when Atlas, a human who has been secretly following him, ends up in his office. Instead of danger, Atlas finds exactly what he’s been longing for — a home, a job, and the sense of family he’s never had. Bel instantly recognises Atlas as his fated mate and hires him to keep him close, surprised by how easily Atlas accepts the underworld and their bond. Their mating takes an unexpected turn when Bel becomes pregnant, something no one thought possible. Together, they must face challenges no other male couple has encountered, relying on their growing connection to hold them steady.

The mate bond between Bel and Atlas gives the story its strongest spark, creating an instant connection that carries them through every challenge. I enjoyed the way their world opened up as they called on different supernatural beings to help solve the mysteries surrounding them — it added fun variety and kept the plot moving even when the emotional beats felt lighter. Their relationship is tested by unexpected twists, and they handle each new obstacle with a united front, which makes their partnership easy to root for. However, the story didn’t offer much in the way of deeper character development or emotional complexity. Most of the feelings stayed on the surface, leaving the characters’ inner lives a bit underexplored. Still, the supernatural teamwork, the solid mate bond, and the steady commitment between Bel and Atlas made it an enjoyable, if not deeply layered, read. This was an MM story with mature content and set in the omegaverse with MPREG.

[Sophie · Rating 4 out of 5]

『••✎••』

｡˚. 🍿I was kindly sent an ARC Copy 🍿｡˚.

Athena has done it again~ I loved this new addition to the massive world of paranormal mates she has created! Bel was such a sweetheart with Atlas and I loved seeing the human being the dominant partner in the relationship! And for the first time introducing MPreg, it was so good! I loved the take on the trope of MPreg, it was done so well and Bel was so cute pregnant, who totally went ham with the nesting! I hope to see more in the series!

I’m very interested to see where this spin off series goes and am looking forward to Mamms story!!! It was so fun seeing all the characters again so I will definitely be doing a reread of the series!

Overall, another great read from Athena! Atlas was such a wonderful addition to the series and I can’t wait to see how much mischief he gets up to with Seb and the other boys!

[Molly Otto · Rating 5 out of 5]

when Bel is sent topside to fetch movie theater popcorn & cherry slushees he doesn't expect Atlas. Atlas is minding his own business working when Bel approaches and Atlas know he must follow the monster to see if he can find out the truth of what happened to his family. I appreciated Atlas and his thurst for knowledge and understanding of this new world, making his transition run as smooth as one could expect from someone new to this world. These two are frigging adorable and court one another before marking and with all their 'helpful' friends you cannot help but question how the underworld runs as smoothly as it does. With a balance of antics of their found family and two souls forming a lasting bond it's a feel-good read all around. Athena dove into the world of mpreg with this story and had a fun take on the genre and utter cluelessness of these demons not really understanding their backgrounds. With a great balance of found family, humor and heat you cannot help but want more from this universe and see who gets stuck with this chaotic family next.

[Katie McCrazy · Rating 5 out of 5]

I was chosen to be an ARC reader for this book.

And LET ME TELL YOU, I LOVED IT! I will be rereading this with my best friend as soon as it officially releases.

For Athena’s first mpreg book, she knocked it out of the park. I was hooked from the first chapter. It has an amazing balance of plot and mystery elements and also the MM romance we all love from her.

I loved to see the unlocked mates characters surface in this book, Asmos was one of my favorite side characters EVER!

The lore - check
The smut - check
The humor - check
The mystery - check
The paranormal elements - DOUBLE CHECK

I can’t wait to read the rest of this series!

[Kristina · Rating 5 out of 5]

I love Bel and Atlas’s book. I love how Atlas followed Bel through the portal without having any clue where it went. I love how careful Bel is trying to be to not overwhelm or scare off Atlas. I love the mpreg, it was well done. Asmos is a great friend, and I can’t wait to see more of him. I really enjoyed the Demon Prince lore. This book is low angst, so sweet, and wonderfully spicy- all my favorite things! I recommend this book!

[Kelly Gress · Rating 5 out of 5]

Love in the Underworld

I enjoyed seeing Bel and Atlas get to know each other; plus it's always fun to see characters from previous books and how they are connected. It was a laugh out loud moment for me when Bel found out why he was feeling so sick. The development after that was some of my favorite parts of the story. I'm looking forward to the next book in the series. I have a growing list of characters that I want to see get their HEA and expand their family.

[Deborah · Rating 5 out of 5]

Fun Read!

Athena Steller writes wonderful books with unique world building. Her writing style keeps the story flowing. I also appreciate that the plot is not predictable.
The main characters in this mpreg are Bel, a demon, and Atlas, a human. I really enjoyed the way they met, and how their relationship developed.
I look forward to more in this series.
Highly recommended!

[Dee Giusa · Rating 5 out of 5]

Bel's Assistant

Bel and Atlas are the cutest couple. This is a super sweet MPreg romance with surprises. Atlas is curious about the beautiful man ( monster) he sees at work and follows him to his happily ever after. Another wonderful book by Athena Steller.

[Maki · Rating 5 out of 5]

AMAZING

I ABSOLUTELY LOVE THIS NEW SERIES!
Bel and atlas and absolutely adorable and sexy and sweet in all the best ways. I love seeing more about the hell realm and the demons lore it was so cool! Can't wait for more.

[Marie · Rating 4 out of 5]

I enjoy this world and was pleased to see so many cameos. I liked the new spin. I did find Bel and Atlas a struggle to see together at times. But with the full cast of characters I look forward to seeing what happens to the next couple.

[Rebecca · Rating 5 out of 5]

too sweet!!! so much extra buttery love

Bel is hilarious and a pushover! Atlas wants to be a hunter, but is too good-natured to pull it off. He is however perfect for Bel!
Ohmigosh! A baby!! Like they don’t know how babies are made…someone should have read the fine print!!!!

[Cris · Rating 4 out of 5]

I loved it! Having the other side of this universe is really interesting, and I can't wait to read the rest of the princes' stories!

[Rachel · Rating 4 out of 5]

3.5 stars

[Jai Oni · Rating 3 out of 5]

Rating: ⭐️⭐️⭐️
Enjoyment: ❤️❤️❤️❤️❤️

[Himom90 · Rating 5 out of 5]

Enjoyable

I enjoyed Bel and Atlas’s story. It’s a fun, low angst, m-preg romance and a nice addition to the series

[FHR · Rating 4 out of 5]

Running an errand for Lucifers mate leads Bel to the one place he dislikes, the movie theatre. Atlas recognises Bel for who he is and a little bit of stalking ensues as Atlas seeks answers of his own. What Atlas discovers is a world he never imagined.
A sweet mpreg story, with meddling found family, humour, spice, nesting and a tease with more interesting characters that you just want to read about.

[julia · Rating 5 out of 5]

Five Stars

I really love this book,can’t wait for the next book in the series, but you have to read The Unlock Mates series and Christmas Satan to get a better understanding of the story. The Main characters are awesome and funny this is a book that I will be re-reading!