What are the spiciest mafia romance books?

Of the 12 mafia romance books smutrecs.com has rated, the spiciest are Den of Vipers (5/5), Dante (about 5/5) and God of Ruin (about 5/5). 7 of the 12 are rated spice 4 or 5, on a scale from 0 to 5.

1. 
   Den of Vipers by K. A. Knight spice 5/5
2. 
   Dante by Sadie Kincaid spice about 5/5
3. 
   God of Ruin by Rina Kent spice about 5/5
4. 
   God of Wrath by Rina Kent spice about 5/5
5. 
   Ryan Rule by Sadie Kincaid spice about 5/5
6. 
   Phantom by H. D. Carlton spice about 4–5/5
7. Broken Whispers by Neva Altaj spice 4/5 · trope tag is an estimate
8. 
   Black Thorns by Rina Kent spice about 3–4/5
9. 
   Brutal Prince by Sophie Lark spice about 3–4/5
10. 
    Our Thing by Nicci Harris spice about 3–4/5
11. 
    Tempted by Deception by Rina Kent spice about 3–4/5
12. 
    Secret Sin by Jill Ramsower spice about 2–3/5

Each book page lists the sources behind its ratings. Ratings marked "about" are estimates. How we rate