Sunday School Friendly Story?

After Boaz had finished eating and drinking and was in good spirits, he lay down at the far end of the pile of grain and went to sleep. Then Ruth came quietly, uncovered his feet, and lay down. Around midnight Boaz suddenly woke up and turned over. He was surprised to find a woman lying at his feet! [Ruth 3.7-8]

Under the circumstances, "surprised" is an interesting choice of words. This is especially interesting because Boaz did not ask Ruth to leave, but instead asked her to stay the rest of the night.

What's more interesting is that, under these circumstances, Boaz defined Ruth as a "virtuous woman."

Now don’t worry about a thing, my daughter. I will do what is necessary, for everyone in town knows you are a virtuous woman. [Ruth 3.11]

And, even further more interesting is the fact that after asking Ruth to stay the rest of the night and calling her a virtuous woman, Boaz told her no one should see her, as a woman, in the threshing area.

I suppose one can read whatever they want to in all this, but, as I read it, these circumstances could have been heavily charged with the energy found between two consenting adults. How could they not have been so? Is this really the Sunday School friendly story I learned as a boy?

Father, I don't want to read something into this story of Ruth and Boaz that is not there, but I want to understand how this could have taken place without natural human elements kicking in...