The Knife of Never Letting Go (Chaos Walking #1) Steaminess Rating

Exactly how steamy is this story?

PG-13

So here's the deal. There is no sex in the book (probably because we're mostly dealing with a world where women are illegal), but there are a few choice sexual innuendoes in the dialogue, which may or may not go unnoticed. Also taking into account the scenes of violence throughout the book, we've decided this was enough to warrant a PG-13 rating.