Okay, look, if we're talking pure spicy escalation, you've gotta zero in on that Hawke reveal and everything that follows. The tension just explodes in Chapter 25, and honestly, Chapter 26 is where things truly cross from simmer to full boil. It's a distinct shift in the series' whole vibe—before that, it's all forbidden longing and teasing banter. After? The gloves are off. The narrative style gets way more... tactile. You know what I mean?
For me, the crown jewel is in 'A Kingdom of Flesh and Fire,' somewhere in the early-to-mid 200s of the page count if you have the physical copy. I won't spoil the setting, but it involves a certain royal and a very determined guard, and it's leagues more explicit than the first book's payoff. The character motivations there aren't just physical; it's wrapped up in all that 'Chosen' and trust drama, which somehow makes it hit harder. It feels earned, not just placed there for the sake of it.
Later in the series, the spice becomes more frequent but, weirdly, sometimes less impactful? Like, you get desensitized. Those first few major scenes in books one and two have a rawness the later castle scenes can't quite replicate, maybe because the emotional stakes were so uniquely high.