Hush, Hush ain't your typical fallen angel/human romance story.
It's not actually all that risque, despite the fact that the main characters meet in a sex ed class. The main impression you get from this book is angst, and hoo boy is there a lot of it. Patch, [SPOILER ALERT] the fallen angel in question, is the bad boy who's simultaneously warm and harsh, and Nora, the protagonist and narrator, just gets sucked past his event horizon. Ther are ups and downs, lefts and rights, 180s and full on loop-de-loops in the roller coaster of the romantic plot.
And that's just one part of the story. The supernatural lore plays a vital role here. I'll admit, it's not as fully fleshed-out as it could be, but the world of Nephilim, fallen angels, and arcane rituals sucks you in and leaves you with more questions than you started with.
If you're a tween who likes angsty romance stories, then I wholeheartedly shove this book in your face, for it is perfect.