This book is so forgettable, I... you know, forgot I read it. All I could think of was that I KNEW I read three books last week. Luckily, I had written it down.
XVI takes place in a future Chicago where government and media control class structure and sexuality in a way that is obviously bad, but otherwise kind of obscure. Girls get XVI tattooed on their wrists when they turn sixteen so that everyone knows they are ready for sex. Because they are so ready for sex, dirty men like to rape them and the police don't believe it's rape. Are you following? This tattoo is supposed to keep them safe for some reason, the only one of which is that they usually won't get attacked BEFORE they get the tattoo. The government is also apparently using the tattooing rite of passage as a way to trick lower caste girls into signing up as sex slaves. I don't even get it. Anyway, the point is that Nina is really scared of sex.
There's a romance here, which is fine. Nina is conflicted at first, of course, because she's so scared, but she loosens up just enough to feel really ashamed and disgusted with herself for making out with her boyfriend on a porch. There's family secrets (yay!) and a rebel underground, which are the cool parts of the book, though they unfortunately don't get too much page time.
Verdict: you can read another book.