LONDON — Britons have strong national views on who is funny (they are) and who is not. “Where would we be without humor?” an old joke asks. Answer: “In Germany.”

Henning Wehn, a German stand-up comedian who insists his job description is not an oxymoron, has heard that jibe more than once since arriving here 12 years ago. As with other jokes about his country, often involving a spot of fake goose-stepping or allusions to the 1939 invasion of Poland, he still laughs — mostly to avoid being told he has no sense of humor.

“Where are we going to lunch?” his British friends are fond of asking, he said in a recent interview. “Is Henning coming? Then we can’t go to the Polish place next door because he is never going to leave.”

A 40-year-old former marketing executive from small-town Germany who did not know what stand-up comedy was before coming to Britain, Mr. Wehn has made a living by mocking dearly held stereotypes in his host country — not least the one about Germans being boring. In one bit, he earnestly explained every last point in a thick Teutonic accent, putting his audience in stitches. (“Stop laughing. I haven’t even explained it yet.”)