Modern and traditional, secular and religious, rich and poor
Despite the technicality of harsh and restricting Iranian law, there are ways to get around this. Most of which involves deception of the local police. It is possible to meet people in coffee shops, pizzerias and at private parties, should you warrant an invite. The latter is probably your best chance for a party holiday in Tehran. The police are there to enforce the law and if you are seen out in public cavorting with a woman, you could be taken in. Generally the tradition is to eat and drink whilst you are out, though not in bars as such, rather social features like cinemas, coffee shops and restaurants.