I looked it up: 20 If, however, the charge is true and no proof of the young woman’s virginity can be found, 21 she shall be brought to the door of her father’s house and there the men of her town shall stone her to death. She has done an outrageous thing in Israel by being promiscuous while still in her father’s house. You must purge the evil from among you. This clearly applies only to women. I think that according to the Bible only woman have to virgins when they marry; for men it is not big deal. The tradition that both men and women are virgin at marriage comes from the Germanic traditions, that we adopted by the Church when Europe was christinised. Tacitus describes in his book "De Germanica" how in the Germanic tradition (I use the word "Germanic" and not German as modern day Germans are just one of the peoples descending from the old tribes) men and woman would both be young at marriage; men 18 and women 16. Also marriage was forever; no divorce. Ideally both would be virginal although even in those days that was not always the case. In the Mediterranean marriage tradition men could be much older than women; they would marry only when they had the means to support their future wife. So pre-marital sex for the man is ok with respect to the Bible itself, although personally I think it is a bit unfair to require virginity only of the woman.