I read a book a while back that I'm still figuring out how I feel about. I distinctly remember, even as a teen, having a discussion with a fellow student about how the descriptive sex scenes in one book we both enjoyed all involved fairly messed up power dynamics while the couples who were generally on even footing tended to get fade to black scenes. I bring this up not to tell you how brilliant a teen I was (although I kinda was) but more to say that I don't really subscribe to the theory that younger people are unable to discern issues in the presentation of a story or that stories aimed at younger people have a standard to uphold beyond providing the promised story.
But. But. But. This story focused on high schoolers, told through one viewpoint. And yes, as both a writer and a reader, first person can be a challenge because that person is (or should) bring their lens, their frame to the story and while a skillful writer can do their best to convey that other characters are feeling differently than the point-of-view character believes, it's still a challenge. Also, it is perfectly fine that sometimes book characters will believe wrong things and not, in the space of the story, have that wrong belief challenged. However, as a reader, it sometimes makes me want to put little virtual post its on the story - great story even though every character in it is terrible about having safe sex. Unless they are not in love. So apparently love makes you forgo condoms, birth control pills, or any sense of concern that your partner might have contracted something from the person they are dating who is not you.