Does Sex Really keep a Relationship?

For a long time now, there have been arguments, some sentiments on what makes a relationship stronger. Why should sex be paramount. Players also use these same route, so how would you know its for real when sex is introduced quick. Heart breaks are more painful because of the deep commitment that was involved (sex). One fact is that the moment a guy gets in there, he begins to feel different (negatively or positively) about you. Does the involvement of sex bring an assurance of love? From experience i know we all have our ways of judging it. What does God say about it? What do you feel? What does the society think? I need your responses.