For several years, the final “Saturday Night Live” episode of the year includes a segment of “Weekend Update” in which co-anchors Colin Jost and Michael Che write jokes that the other must read for the first time on the air. For Jost, this typically has meant Che forces him to say a litany of jokes about race and racism that are horrifically tone deaf and over-the-top — and, in context, often quite funny.

This year, however, Che found a new way to torture Jost: Making him say outrageous things about his wife, Scarlett Johansson — while a camera captured Johansson’s live reactions in the hallway outside of the studio. The actor appeared during the episode’s cold open to welcome host Martin Short into the Five Timers Club, and Che apparently could not resist the chance to have some fun at the couple’s expense.

The bit started with Jost reading that this year,...