“Come and knock on our door…” Sorry, the sight of Joyce DeWitt at off-Broadway’s Miss Abigail’s Guide to Dating, Mating and Marriage brought on a Three’s Company moment. Presumably, DeWitt and Miss Abigail star Eve Plumb—still known to most of America as Jan Brady—had plenty to talk about as vets of classic ’70s sitcoms. Appropriately enough, DeWitt took in the comedy on April Fool’s Day at the Downstairs Lounge at Sofia’s, then enjoyed a chat with Plumb backstage. Head over yourself if you’re in need of a little relationship advice—or just a laugh.