Am fashiku olamilekan,well, sex before marriage, i will say there is nothing bad in it but the question here is that is God in support of it,  like me what i do i think of God in whatever i do even before taking the step. but if the 2 people involved seat down and agree that this is what we want and they are ready to take it to marriage good it's not bad, not that you will sleep with her and after you dump her for another lady.