The takeaway here is that the heterosexual love between a married couple is a divine gift and to be treasured. It’s a straightforward book.
Some other, random and unprofound, thoughts: This book is also called the “Song of Solomon”; note the third-party reference to King Solomon in 3:9. In addition to hot passages (see, e.g., 5:5 and 7:9) and favorable attention to female breasts in particular, there are some outrageous similes (4:1-5, 6:5-7, 7:1-9). And note the shifting pointing of view, from female to male (the New American Standard Bible has footnotes for “Bride,” “Bridegroom,” and “Chorus”).