Is premarital sex against the Bible?

It's only premarital sex if you never intend to get married.

Saw that on a t-shirt.

Everything centers around sex. Most sexual abuse takes place in religious places. Don't worry too much about any holy book they turn you into eunuch.

.....it's easy for critics and skeptics to argue that the Bible has nothing to say about pre-marital sex. That's because they're usually looking for negative statements. They want a "condemnation" or a "thou shalt not." But the Bible expresses its perspective primarily in positive terms.

And I've also heard it expressed that we should be more concerned that it happen "after marriage rather than whether or not it happened before marriage.

My own personal experience would be that genital sexuality belongs in marriage and becomes less meaningful and fun without that commitment of the transcendental self that a man and a woman make to each other in the marriage vows.

And a good marriage always has a reason to be celebrated in sexual intercourse.