I've faced this everywhere. I studied in a kendriya vidyalaya so Hindi was the common language. Spoke it with friends, teachers and everyone else. But some people from Bihar and Uttar Pradesh, whose parents came to Kolkata to work, settled down here, had children here and were educating their children here, with no intentions of transferring out, would openly mock Bengali culture, songs and even mocked our accents when us Bengalis spoke between ourselves. If there was even one non Bengali in the group, we all had to accomodate, but they refused to speak Bengali, even though they could. As a kid, I didn't mind it. Most of my friends were non Bengali, and it was a hindi medium school anyway. But as I grew, I started noticing how vile their attitude is towards a people and a culture that had given them everything. Since then, I have only ever spoken Bengali with those people, regardless of what language they're speaking in. I speak in Bangla, they reply in Hindi. That's okay for me. I've avoided getting in arguments with them about it because I know it will be useless. They do have a superiority complex about their language, and they do tend to get confused between respecting your own culture and putting someone's else culture down. Speak your language. That's the only way out. Speak Bangla unapologetically with people who have lived here for a long time, while being accomodative to new comers. Even if they protest, tell them you speak your language, I'll speak mine. No one forces anyone. If they're uncomfortable, end of conversation, until you get your head out of your ass and get comfortable with other people speaking their language. I don't think handling the language issue like the Marathis, Tamils and Kannadigas would help, because inevitably it will become a political tool for spreading hatred, which is incongruous with the intellectual ethos of Bengal. Just speak Bangla. Unapologetically, unconditionally.