Not sure about Greece but here in the U.S. multi-generational households have become a bit more common as more people struggle in the economy, so it's not as huge a deal. My brother and his wife got their own place only months before getting married. Prior to that they were both living with her mother, because my brother has been attending college (almost finished now), and he simply could not afford all of his own living expenses while also putting himself through college. This did not stop him and his lady from dating for years, though. I think it does help if your partner comes from a similar economic background, though, so that there is genuine mutual understanding.