The Book of Romance by Tommy Nelson

This is also framed as a quasi-commentary on the Song of Songs (which is precisely why I was reading it now) and Nelson also focuses more on application than in depth study (hence the quasi) however I find more sense in the ideas put forth.

While I may not agree with all of his propositions they are largely issues not relevant to the points being made.

One thing I really appreciate is the distinction he draws between dating and courting considering them equally valuable but for different purposes. The case he makes for the inclusion of both in the way we do Romance is compelling.

I would absolutely recommend it, but you may want to skip the Honeymoon chapter because he is not bashful when explaining the meaning behind the metaphor.