http://www.desiringgod.org/ResourceLibrary/AskPastorJohn/ByTitle/3371_What_would_you_say_to_a_young_man_who_is_considering_sleeping_with_his_girlfriend

The following is an edited transcript of the audio.

I would say all of that to the woman and add this: "If a man wants you in bed, you don't want that man. Period! You don't want him! If that man is willing to use you outside the covenant of marriage, why wouldn't he use another woman outside the covenant of marriage ten years from now?"

I'd add that to the woman. You could say it to the man. But I think the man bears a very unique responsibility here, because women desperately want to be loved. And they will yield more than they should if they feel that in order to keep him this is the way she has to do it. And I would just plead with her that she doesn't need that.