This book is awful.
Don't get me wrong - it's pretty well written; there's no real problem with grammar, sentence structure, or spelling (though I'm not sure the authors really knows what 'domineering' means. Does a domineering man really have a domineering expression, even whilst driving?). Mind you, there's some clothing issues during an early sex scene - she takes off her dress, then instructs the male character to remove her pants, then when redressing, the dress has become a shirt.... Hardly a good sign, when the authors have lost focus during one of the first sex scenes.
The problem is, the characters and plot appear to be sprung from the mind and imagination of a fourteen year old. Or two fourteen year olds, given the dual authorship.
The female MC, Iris, is allegedly 18. Apart from fucking her guards, there's no mention of school, jobs, friends. She apparently spends her days....doing nothing and not giving much thought to her father's life of crime. He's apparently a 'mafia boss', but the kind where dealing in crime (per the imagination of CHILDREN) means he works in a shop, selling swag bags and boxes labelled 'crime'. Because she not only has no idea what he actually does, she is shocked and appalled (SHOCKED AND APPALLED), whenever anyone else commits a crime.
For real, she accompanies a man she knows to be an assassin, to an assassination, and she is shocked and appalled that he is breaking in to his intended victim's home. She knows he plans to kill him, but breaking through his front door is a bridge too far!
She resents being called a spoiled brat, yet has never done anything apart from sit at home being spoiled. She has no skills and no evidence of any natural intelligence. No job? Ok, assuming super wealthy. What are her hobbies, her interests, her pursuits? Nothing worth a mention apparently. She screams and shrieks constantly. Her vague attempts at 'plans' are embarrassing and she fails miserably every time, yet her arrogance and entitlement knows no bounds. When googling known associates of her revenge target, she does appear to be able to locate photos, court records and the location of the street corner they frequent though, which is something of a super power, if an....unrealistic one! She's also shocked to discover that her father's murderer had prior dealings with...her father (as opposed to orchestrating a purely random hit on her father and all his guards...?). The concept of motive seems to be a foreign country.
With regards to character relationships, she fucks Sirus and his two sons (hence the reverse harem categorisation, which seems to feel it's super daring and taboo, yet Sirus seems completely ambivalent to her interfering with his sons, which just comes off as disillusioned and uncaring. I have no problem with reverse harem, btw - though finding decently written ones is a. Chore. Just that I can see why sons may have an issue with someone also sleeping with their father) yet fails to comprehend why this may annoy them and even if she can comprehend it, shrugs and carries on because 'she just can't help herself'.
She is essentially the worst kind of female stereotype in fiction - the kind usually set up as the 'mean girl' in American high schools, yet this time, she gets everything she wants and needs because, whilst dumb as a box of hair, she is pretty. And fucking stupid.