We must read carefully and often. I am often exasperated by the average person’s lack of interest in the portion of the Bible that Jesus and Paul knew and loved.
Notice where this story occurs. Some folks in Seminary who should know better are annoyed that it was included “by mistake” in the middle of the Joseph story. The Bible does not make mistakes!
There is a contrast between the behavior of Joseph and the behavior of Judah. The loving of Joseph towards others and the rather unpleasant behavior of Judah. The last verses in the previous chapter tell about the anguished sadness of his father at losing his son and a sneeze later Judah leaves his father and leaves the land given to Abraham by God and goes to the Philistines. He went to a land where the God’s were feared, not loved, and the motivation to go to the temple was that the priestesses were prostitutes. Worship was not an spiritually uplifting experience.
An interesting sidelight is that today in India, many girls serve the Gods by providing similar services in exchange for some money in the collection plate. Satan seems to have found a way of destroying a soul with the crude desires of the body.
He marries a Canaanite as you point out, but notice his rather abrupt behavior, no love or courtship is recorded in the Bible the way it does in so many other storiesHe marries her and sleeps with her in one breath. He saw her, marries her, and sleeps with her. A hint of what will happen with Tamar. No grief seems to be recorded at the death of his wife and sons. His sons are wicked and he seems to value the last because he is his heir.
He leaves off mourning and on the way to care for his sheep, spots Tamar and skips the small talk. He is blunt about what he wants. He is rough enough to give her some things that he should have been more cautious about. His staff, his staff, and his cord. With a sort of impatient need to make love to her, he ignores the fact that these are his credit card and the deed to his property. In the suddenness of his encounter, there is no mention of house or bed. Just grab and run. Sorry if I seem a little annoyed, but this is not how anything that has the label of love on it should happen.
I am both amused and annoyed that he doesn’t look at her veiled face which would have alerted him to who she was. No kissing and quiet conversation here.
Later when he discovers that SHE has misbehaved, his words in the Hebrew text are “Take. Burn.” When he sees that staff, the cord, and the seat, he says, “She is legally more correct than I am.” Sort of a dubious. “I’m sorry.” What a rascal!”