[This story contains spoilers from season 12, episode eight of Curb Your Enthusiasm, “The Colostomy Bag.”]

Conan O’Brien made his long-awaited cameo on the latest episode of Curb Your Enthusiasm. The talk show host — who is a close friend to creator-star Larry David in real life — appeared on the HBO comedy as a high-profile neighbor, someone TV Larry (played by the real David) felt he needed “clearance” in order to approach.

For the final season’s eighth episode bit, Larry sought out his friend Richard Lewis (who also played a version of himself on the series) to help him get permission to approach the comedian but, due to the episode’s chain of events, clearance doesn’t come in time when Larry ends up needing a big favor.

So Larry arrives, unannounced, at O’Brien’s home, begging for “emergency clearance” because his car died (Larry angered a valet, who unplugged his electric car) and he’s afraid that Susie Greene...