Some guy, assuming spike was vietnamese (because his profile said so), asked why vietnamese eat people.
Spike goes into a lengthy explanation that just because he selected vietnamese as his nationality in his profile, does not necessarily mean it is true. The guy then says ok I understand you, but you havent answered my question about why vietnamese eat people.

It's funny because Spike went to the effort to explain he is not vietnamese, and the guy continued asking him questions relating to vietnamese people.

NB: I am pretty sure vietnamese do not eat people!