A partial list of things the Old Testament teaches or suggests about sex, marriage, and relationships:
1. Kidnapping and rape are perfectly acceptable ways to find a wife. (Judges 21: 16-23; Deut. 22:28-29)
2. Don’t underestimate the benefits of visiting prostitutes. (Joshua 2)
3. Use sex to get power. (Entire book of Esther; see discussion here.)
4. Women, make yourselves sexually available to powerful men. (Esther.)
5. Men, spice up your relationship by offering your wife to local political leaders for sex. Twice! (Gen. 12:10-20; 20:1-16)
6. Writer’s block? Go marry a prostitute, then mock her in your writing. (Hosea.)
7. Men, if you’re in danger of rape, suggest the would-be rapists rape your wife (and/or your host’s daughters) instead. (Judges 19)
8. Women, overlook indiscretions like mistresses and occasional murderous rage, as long as the guy is powerful. (Esther)
9. Suspect your wife of cheating? Take her to the priest for a cool magic ritual that will make her barren if she’s unfaithful. Woot! (Number 5:11-31).
10. Feel free to make sex slaves out of female captives, but only if they’re virgins. Otherwise, kill them all. (Numbers 31:7-18)
Also: Polygamy is fine (e.g., Gen. 25; 2 Sam. 19), and homosexual behavior is sinful (Leviticus 18:22).