Hiya, just seeing this. So sorry.
I didn’t justify sin, I said the Bible does not expressly say “abstain from premarital sex”.
Let me take you back to your own Bible verses, all except Mr 7:21 says “sexual immorality”. Only Mark mentioned fornication (which refers to premarital sex.
Sexual immorality is both pre- and extramarital affairs.
The point I was driving at is this: people misquote the Bible to forbid premarital sex but majority of those verses are actually not exclusively referring to premarital sex. Of course premarital sex is a sexual immorality, but it also includes extramarital, masturbation, lust and “thinking about it in your mind” (Matt 5:28).
So you can be a virgin and be an adulterer because you have slept with the person in your mind.
Do you get my drift?