Generic Ethnic Joke

A person belonging to an ethnic group whose members are commonly
considered to have certain stereotypical mannerisms met another
person belonging to a different ethnic group with a different set of
imputed stereotypical mannerisms. The first person acted in a manner
consistent with the stereotypes associated with his ethnic group, and
proceeded to make a remark which might be considered to establish
conclusively his membership in that group, whereupon his companion
proceeded to make a remark with a double meaning, the first meaning
of which could be interpreted to indicate his agreement with his
companion, but the other meaning of which serves to corroborate his
membership in his particular ethnic group. The first person took
offense at his remark, and reacted in a stereotypical way!