One of the most influential people in my life was a professor at Rochester College, Dr. David Fleer. If you're curious, he now teaches at Lipscomb University. One of the many courses I took under Dr. Fleer was Survey of the Old Testament. If you were to teach Song of Solomon to a bunch of hormonal college students, how would you tackle the subject? I think he handled it with great aplomb...well, great aplomb after yelling down the hall that we would be talking about sex in class that day. His take on Song of Solomon was pretty straight forward, "Fire is good in the fireplace."
There's a whole strand of Christian tradition that interprets Song of Solomon allegorically (to be fair, there's a whole strand of Christian tradition that interpreted the vast majority of the Old Testament allegorically). In this train of thought, the love story we find in Song of Solomon has nothing to do with physical desire or sex. Instead, Song of Solomon is about Jesus's love for the Church. Now I can completely understand why a monastery full of celibate monks would find a way to interpret a book about sex so that it has nothing at all to do with sex...AT ALL! But seriously, Song of Solomon is about sex.
Maybe the saddest part about our uneasiness with sex, and therefore the book of Song of Solomon, is how gnostic our thinking is. Sex is just too physical. It's messy. Animals do it, and so, for many people, the act of sex is something that lowers their humanity. To broaden our view, it's sad how much of the Bible is read through a gnostic lens. In that regard, some people may be uncomfortable with the book of Song of Solomon specifically because it undermines that ideology. Sex (physical, messy, and animalistic) is created by God, and when all was said and done, God said it was "very good." All of it, as it was. Physicality isn't the opposite of spirituality. They are, in fact, part of the whole of God's creation. Therefore, a book entirely dedicated to love and sex has it's place in the canon of scripture.
At the same time, maybe you parents out there might want to follow the ancient Jewish tradition of not letting your children read it until they are forty. I'll leave that for you to decide.
Stopping point: Song of Solomon 8