Mashmont
Virginity is never stipulated as a requirement of the Israelite people before marriage, the only exception being that a priest can only marry a virgin according to Leviticus 21:13-14.
Also, in the Old Testament, whatever expectation that people had concerning being virgins was only applied to women, and then only within the context that a groom demands his wife be a virgin. Virginity before marriage was never considered a religious virtue in and of itself.
Furthermore, men of Old Testament times regularly engaged in polygamy or had concubine.
These practices were commonly accepted and never explicitly condemned; so how is the Bible in any position to pontificate to us today concerning the now-common practice of premarital sex?
Also, there are a number of anecdotes of premarital sex, such as Abraham begetting Ishmael with his wife's slave, Hagar, and also Jacob begetting sons with his wives' slaves Bilhah and Zilpah.
These anecdotes never state or imply that there was anything wrong with these actions.