Sex before marriage? What does the bible say?

I was in a bus today, and i overheard some students arguing about having sex with just one girlfriend or boyfriend. As long as their sex life wasn't with several unmarried spouses, they felt it was okay with God. "show me the verse or chapter in the bible that goes against me sleeping with my girlfriend". Those where the words of the guy sitting behind me. Hmmmm, continue reading....
You shall know the truth and the truth shall set you free(lol....).Here are ten bible verses that will set you free

1 Corinthians 7:1-40 

Now concerning the matters about which you wrote: “It is good for a man not to have sexual relations with a woman.” But because of the temptation to sexual immorality, each man should have his own wife and each woman her own husband. The husband should give to his wife her conjugal rights, and likewise the wife to her husband. For the wife does not have authority over her own body, but the husband does. Likewise the husband does not have authority over his own body, but the wife does. Do not deprive one another, except perhaps by agreement for a limited time, that you may devote yourselves to prayer; but then come together again, so that Satan may not tempt you because of your lack of self-control.

Hebrews 13:4 

Let marriage be held in honor among all, and let the marriage bed be undefiled, for God will judge the sexually immoral and adulterous.

1 Corinthians 7:8-9

To the unmarried and the widows I say that it is good for them to remain single as I am. But if they cannot exercise self-control, they should marry. For it is better to marry than to burn with passion.

1 Corinthians 6:18-20 

Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body. Or do you not know that your body is a temple of the Holy Spirit within you, whom you have from God? You are not your own, for you were bought with a price. So glorify God in your body.

Exodus 22:16 

“If a man seduces a virgin who is not betrothed and lies with her, he shall give the bride-price for her and make her his wife.

1 Corinthians 6:18 

Flee from sexual immorality. Every other sin a person commits is outside the body, but the sexually immoral person sins against his own body.

1 Corinthians 7:2 

But because of the temptation to sexual immorality, each man should have his own wife and each woman her own husband.

Genesis 2:24 

Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh.

Galatians 5:19-21 

Now the works of the flesh are evident: sexual immorality, impurity, sensuality, idolatry, sorcery, enmity, strife, jealousy, fits of anger, rivalries, dissensions, divisions, envy, drunkenness, orgies, and things like these. I warn you, as I warned you before, that those who do such things will not inherit the kingdom of God.

Colossians 3:5 

Put to death therefore what is earthly in you: sexual immorality, impurity, passion, evil desire, and covetousness, which is idolatry.

See, the bible is clear. I know its not easy, i no holy pass o (loools). Its an issue that God does not take with levity. If you have a spouse you aren't married to, the best thing is to avoid being alone, Trust me its only a matter of time, you ll be glad you obeyed God. It makes your marriage sweeter at the end of the day.