Sexual sins not mentioned in the Bible

The Bible mentions a number of sins having to do with sex. Adultery, which is violating the marriage covenant, is so important a misdeed that it is mentioned in the Ten Commandments. Homosexuality is presented as a sin. Some sexual sins, all of them specific prohibitions (don't have sex with an animal, or with your sister) are listed in Deuteronomy 27. But the Bible doesn't cover all sexual misbehavior. The New Testament is probably more about our attitude, our relationship with God, than about setting forth all the possible dos and don'ts. The Old Testament, too, can be summarized in the commands to love God with all our heart, and to love our neighbor as ourselves. If we do these things -- and we need divine assistance to do them -- we will meet God's behavioral standards.

Here are some sexual behaviors that I believe are sinful, but that are not specifically mentioned in the Bible, so far as I know:
* Having sex with a child. I suppose we should have sense enough to know that is wrong, without a scriptural prohibition. The Golden Rule, and the "love your neighbor" also prohibit this.
* Although both prostitution as a part of idol worship, and "ordinary" prostitution, and the use of prostitutes, seems to have been considered wrong, there is nothing direct in the Bible about pimping -- making arrangements between prostitutes and customers.
* Jesus said that looking on a woman to lust after her was a form of adultery. He didn't say that for a woman to look on a man in this way was a form of adultery, but it must be. So, I guess, must homosexual look-lusting be sinful.
* There is nothing in the Bible about sex slavery.
* Using, and producing, pornography must also be sinful, because it's lusting after images of someone, or helping someone else to lust after such images.  
* The Bible doesn't say so, but using sexual images or other stimuli to sell merchandise seems to me to be sinful.
It seems to me that all six of these behaviors are sinful, although the Bible doesn't specifically say so. Probably the last three of these weren't really possible in Bible times. Unfortunately, they are now.

The Bible does indicate that sex outside of marriage between a male and a female, committed to each other, is wrong, in many ways. But see here -- I was surprised at how little the Bible really says about this.

Stay pure. 1 Corinthians says that there is hope for us when we haven't been pure in the past:
1 Corinthians 6:9b Don’t be deceived. Neither the sexually immoral, nor idolaters, nor adulterers, nor male prostitutes, nor homosexuals, 10 nor thieves, nor covetous, nor drunkards, nor slanderers, nor extortionists, will inherit God’s Kingdom. 11 Some of you were such, but you were washed. But you were sanctified. But you were justified in the name of the Lord Jesus, and in the Spirit of our God. (World English Bible, public domain)

Thanks for reading.