There are many reasons why Pinoys are hesitant to mingle with their fellow Pinoys.. some have already been pointed out..
but another possible reason is that some of them have no proper visa and are staying here illegally.. it would suit them not to socialize too much to avoid being detected.. we Filipinos call them TNTs or "Tago-Ng-Tago" (meaning always hiding).. I know someone who lives in London and true enough, she avoids having contact with a lot of people, esp Pinoys..
can't be true to everyone but just sharing an idea..
