In today's reading, there is a provision for the Israelite men to marry a foreign woman. At first this sounds like a contradiction. Earlier God had warned them against marrying the inhabitants of the land saying that the foreigners would lure them away from Him. This provision is for marrying a captive woman. This woman would be considered "spoils of war"." The captive woman has no ties, no family, or anyone to support her in drawing the man away from God.

At the heart of the marriage relationship is the idea of faithfulness to the vows of commitment. Faithfulness is important both in marriage and in the people's relationship with God. Their unfaithfulness to God is considered spiritual adultery."
-quote from the Chronological Bible comments

Spiritual adultery happens when believers in Jesus break their vows of commitment and follow after other gods.

In Lev. 18 homosexual practices are forbidden.  This was confirmed by Paul in his letter to the Romans. 
Rom 1:27 
Likewise, their men have given up natural sexual relations with women and burn with lust for each other. Men commit indecent acts with men, so they experience among themselves the punishment they deserve for their perversion. 

Deut 22:5 forbids women to wear men's clothing and men to wear women's clothing.  Many people use this verse to say that women shouldn't wear pants. But what kind of clothing did men wear at the time this was written?  They didn't wear pants like men do today.

According to the law, the penalty for adultery is the death of both parties involved.
(Deut 22:22, Lev 20:10)

There is a New Testament connection.  When the teachers of the law and the Pharisees brought to Jesus a woman caught in adultery, notice they didn’t bring in the man with her. (John 8:3-11) Could it be that some of those men who were standing around the woman were guilty themselves? Is that what Jesus wrote on the ground…their names or their sins?

All the woman's accusers left, one by one. Jesus told the woman that He didn't condemn her. But He also declared. "Go now and leave your life of sin."

The sin is condemned, but not the repentant sinner. Praise God for that!