So I had to see if all the books in this series were like the first one I had read, totally PG and sappy to the extreme. And they are!
I mean, this one is probably closer to PG-13, as they do actually have sex. But through the whole story, Erin the MC is terrified that her childhood friend is going to reveal a terrible secret from her past. The friend holds this secret over Erin's head throughout the whole book and it comes across as a seriously juicy secret that this malicious bitch is going to reveal to everyone and it'll ruin Erin's whole life, her marriage, etc. So you're like "Oh damn, this bitch must've murdered somebody or something!" and then the big reveal: she stole 3 candy bars when she was a starving 12 year old foster kid.