People ask this question because there is no reference to God or the Law in Song of Solomon and it seems explicit in celebrating sexual love. Through the centuries it has been one of the most controversial books in the Bible.
True wisdom requires us to read God’s Word with the goal of practical application, not merely intellectual stimulation.
The Song of Solomon is an intimate, tender, romantic expression of physical love between a man and a woman—first, prior to their marriage…then, after the wedding. If anything other than this is to be safely seen here, it’s an analogy related to Christ and His devoted love for His bride, the church.