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.

Of course, the first person took offense at his remark, and reacted in a stereotypical way!