Suffice to say, I tend to speak Cantonese when I have Chinese friends around, and yes... I do translate what we are talking about. Please don't take this as being rude or ignorant, but for me personally, I find it hard to speak Chinese when I am away from home. And when I do meet up with Chinese friends, we have Irish friends with us also (and other nationalities whose English is not their mother tongue of course).
But I would try to speak in English as much as I could. It does not help that a group can sometimes be split because of this, and I have to try and bring everyone back together (but you know, after a few pints, we all forget).
Heh... I just wonder if anyone who have had this experience as well?