Premarital sex puts too much pressure on a relationship. Either to break up, or rush into marriage. Sex is not a suitable foundation for marriage.
I have a friend who meets his girlfriend, he doesn't even call her a girlfriend BTW, at a public common place, never at either of their homes, to avoid temptation.
Sex can come later, AFTER MARRIAGE. The relationship should be build on something far more solid than sexual urges. To show proper respect for the one you wish to marry or mate with, do it right, let sex come LATER at the appropriate time, after having made it official, one's commitment to marriage. If one is not ready to form the stable family and commit to marriage and possible children, one is not ready for sex.
Women need to be loved, men need to be respected. Showing the respect to wait until the appropriate time, and getting things in the proper order, help insure that these needs will better be met.