No sex outside of marriage is fine according to God. It is called fornication, and will keep one from becoming a child of God if it isn't repented of:
Hebrews 13:4 Marriage is to be held in honor among all, and the marriage bed is to be undefiled; for fornicators and adulterers God will judge.
I Corinthians 6:9-10 Or do you not know that the unrighteous will not inherit the kingdom of God? Do not be deceived; neither fornicators, nor idolaters, nor adulterers, nor effeminate, nor homosexuals, nor thieves, nor the covetous, nor drunkards, nor revilers, nor swindlers, will inherit the kingdom of God.
SealedEternal