There are many stories in the Tanach about innappropriate intimate relationships, such as Yehuda and Tamar, Lot and his two daughters, and, at least on the face of things, the initial connection between Ruth and Boaz. How do we reconcile the fact that Ruth courted Boaz in a way that is not the way of Torah law?
There are many books in the Tanach that focus on the intimate relationship between man and woman, such as Ecclestiastes and The Songs of Songs (Kohelet and Shir HaShirim).
The answer lies in partially in Shir HaShirim - a book that is dubbed "The Holy of Holies" - by Chazal. How can a book who's verses talk about an intimate relationship and physical love between man and woman. However, Chazal instructed us to read deeper into the text and take the verses as a metaphor, and not a literal description of physical intimacy. Each part of the body is an analogy for a part of the Jewish people, and their connection with God. The Book of Ruth should also be read as an analogy, beyond the literal meaning of the words.