"Some see here Solomon and Pharaoh’s daughter only – they are short-sighted. Others see Solomon and Christ – they are cross-eyed. Well-focused spiritual eyes see here Jesus only." Got this off Richard Brooks, who preached a sermon series on Psalm 45. The title of the first one on verse 1 - A Heart Full of Christ - is enough to make you want to listen to the whole series!
He also has a commentary on the Song of Songs published by Christian Focus.