This is quite a controversial question, and there is no consensus in the plan — to have sex in the first days of acquaintance, or should I wait? All, of course, depends on what we want from this relationship. For example, if we only want sex then why not.
But it so happens that we needed a relationship, and flying immediately to sex we can miss the beauty of the romantic component of the relationship.
for Example, recently I worked as a psychologist, sexologist and psychotherapist with my client from Moscow for her sexual problems. She said she "doesn't want a husband." In such cases, you can go back there to find resource state of love, when there was no sex. Maybe it was petting, but not sex. And she had nothing to remember, sex was immediately on the first day, and had not received its development in terms of friendship, mutual understanding or "being in tune".
Or my other job as a psychologist, psychotherapist and sex therapist with a couple, where sex has been from day one.When sex moved down, working a couple were impossible to catch because initially, the relationship did not begin with, why would a man ( he himself said about it as a problem). And the girl saw him immediately decided that this is her future husband. In the end, the relationship was doomed, as was passed the threshold of no return, when the relationship can no longer be restored. And I was already an experienced psychologist, psychotherapist and sexologist worked on module raslablenija to release the girl from problematic feelings.
So, decide for yourself what and how, it all depends on you and the goal you are pursuing.