Is Sexual Abstinence Realistic?

Today's question says "in this post-Christian nation, is it realistic to tell our children to be sexually abstinent? I know that is the biblical position, but the statistics are what they are regarding premarital sex. Would a good fallback position be abstinence unless you are with someone you deeply love and are looking to marry? I know it might sound a defeatist, but I'm worried about Christians making decisions and not being safe and all the potentially terrible consequences that might follow."