Proverbs5 is the first proverbs, so far, that has a title, & whole section, over one specific sin: sex outside of marriage [fornication(sex befor marriage)& adultery]. I have 2 points from Proverbs5.
1) Verse5 says, "For she cares nothing about the path of life. She staggers down a crooked trail & doesn't realize it." (NLV). That's saying even though that person is living in constant sin, they don't know it. I went to MACU Mash this past weekend, & had the luck of getting a class with Cliff Sanders, Bib Life & Witness. One of his points for that classe's lesson was that people don't always know if they're sinning, they may think they're doing nothing wrong.
My second point is that there is consequences listed for sex outside of marriage. The listed consequences are: 1) loss of honor & all you have achieved (v9), 2) strangers will get everything you work for (v10) , & STD's (v11). STD's is a growing problem in our world, & outside of poor medical care, it's because of sex outside of marriage, any kind of sex outside of marriage.
The third point of this is the same as Proverbs1-4, if you listen to GOD, life will be easier. We'll be able to get through hard times easier, & we get to enjoy his love, but if we ignore him, life gets alot more difficult.