Thousand times this. The biggest mistake my parents made, was giving up on their mother tongue to help me learn a language they were not fluent in. I did not learn the new language from them, I learned it from school, reading books, movies and all sort of others things which were present everywhere. Their decision only made socialising with other cousins and family members difficult for me, made unnecessary overhead for our inter-family communication, made me in fact segregated. If you have kids, let your kid master their parents mother tongues and flourish.