Of avoiding English

Today at work, a vendor called. He had principally been communicating with my senior before this, and I think I have only spoken to him once when my senior wasn't around. The conversation went something like this (irrelevant parts omitted):

Vendor: (speaks Mandarin) Can you speak Mandarin?
Me: (in Mandarin) No [I remember laughing then, because it is rather funny saying you cannot speak a language in the language you are saying you cannot speak :P ]
V: So you can only speak English and...German, no, French? [I guess my senior told him...he likes to "report" to everyone that I can speak French -_- Like it's any use... ]
M: Er...yes.
V: Not even Hokkien?
M: Hokkien, yes...
V: Then let's speak Hokkien, more friendly
M: Okay...
V: ... (sounds like he's having difficulty finding words)
M: English also can
V: (speaks in English)

Hi hi ha ha ho ho..... I guess Hokkien isn't really good for a formal setting.

And...how is Hokkien more friendly?? I guess it's more friendly when the other party doesn't like speaking English...