At what point in a relationship is it time to take it to the next level?

I know that the rate that you move ually with your significant other all depends on how you feel for them, how they treat you, if you love them or not blah blah blah. What I want to know is how much time do you think it should take to move to the level of with your significant other? I know that it is different for every person. But I am writing an editorial on how ruins relationships for TEENS...not mature people who know what they are doing. Now some teens are mature and are aware of what they are doing...but most aren't. So I need to know at what point in a relationship do you think it is time to move to the next level and sleep with your significant other.