My wife works in a small Pre-School, in West Virginia, in a small town with population of no more than 2500, if that.
There are parents who let their 3-5 year old kids watch heavy "R" movies with them. Of course, there was also the four year old bragging that he was now old enough that Mom let him play on the train tracks by himself.
I was in high school clear back in the late 70's, and watched as hash was cut in class for sale. Pot was common. Kids touching in the hallway wasn't uncommon, though I understand its a lot more prevalent now.
One of the young women I work with admitted she had sex the first time at fifteen, on the cement floor of her boyfriend's basement while his parents were out, and "definitely felt pushed into doing it".
Long and short of this post, its hard to tell where to draw the lines of morality in a morally vague world.
My opinion, write your story. If drugs and sex is part of the story, include them. Personally, I find a teenager story without sexual tension to be questionable. Seriously, this isn't the eighteen hundreds.
I will close with simply this:
For those adults who think their kids should be shielded, allow me to quote a banner from a local university.
"Father's, thank you for your Freshman Daughters"
In the end, it's pretty simple, you can educate your kids, or someone else will do it for you. If you find an "edgy" book in your teens room, maybe it's time to sit down and talk with them about it instead of at them. Instead of confiscating it, utilize it as a teaching tool, to open the doorway to discuss their opinion on sex and drugs. Maybe even do that thing called listening. Something I don't think enough people do these days, as many seem too busy judging and prowling for something to fight about than to sit down and have a real discussion.