A Taipei city official mocked opposition mayoral candidate Puma Shen with a string of Mandarin homophone jokes, and Shen fired back with one of his own — a sign the race is getting personal.

• Taipei mayor Chiang Wan-an has long been accused of dodging questions, earning him a nickname built on a wordplay about answering "B" when asked "A."
• A city research chief flipped that jab onto Shen, calling him a lawmaker shielded by minders who also answers the wrong question, and accusing him of running away from a set of tainted-oil questions asked five days earlier.
• Shen, campaigning in a Taipei park, paused, sighed, and shot back with a pun on Chiang's own name meaning "just don't refuse to listen."
• The exchange is really about Shen's silence on the tainted cooking oil issue, which Chiang's side wants to keep in the headlines.

Outlook: Expect the tainted-oil questions and the nickname war to keep driving the Taipei mayoral campaign in the coming weeks.