Sarah and Bob, expecting their first child, are hosting a birthday party for Sarah's mother. Sarah's brother, Joel, arrives early to tell Sarah some news he's put off telling anybody: He's gay. Joel's date, Randy, is not the nice Jewish girl pediatrician Joel led his family to believe, but a nice Jewish boy pediatrician. Joel, divorced and about to enter a custody battle over his two sons, has picked this evening to come out of the closet to his parents, especially since he knows his homosexuality will be brought up in court. Joel and Sarah's parents, Abe and Miriam, arrive, looking forward to meeting Joel's new girlfriend. When the doorbell rings, however, Joel chickens out and won't let Randy in. Bob volunteers to talk to "her" and goes outside. Moments later, Joel opens the door to Bob—dressed in drag, pretending to be Randy, and the hilarity begins. Abe and Miriam instantly like Randy and the party, including the ruse, is a great success, with the evening ending with Sarah going into labor. Eight days later with Sarah and Bob are hosting their new son's bris. The mohel, Dr. Rosen, arrives and completely surprises Joel. Dr. Rosen, it turns out, is Joel's boyfriend, Randy! The tension builds and for Abe and Miriam's benefit, Bob again dresses as Randy (the girlfriend), only this time he must do double duty as himself as well. The humorous antics keep them all busy but when a bagel is dropped under a table, and Randy goes to retrieve it, it is Bob who comes back out. The truth exposed, Joel admits his secret to Abe and Miriam, who are relieved. They knew all the time, and they're just glad one of their children ended up with a doctor! Now at ease, everyone vows to help Joel win his custody fight, and when Randy identifies the judge as an old paramour, they all know they have little to worry about and can enjoy life as an open, loving family.
"In a small, special field of sentimental Jewish family comedy, where absolutely nobody does it better than he does, Jim Sherman has written his best play yet, JEST A SECOND!" —Chicago Tribune. "…trust me on this: JEST A SECOND! is very funny." —Wall Street Journal.