The Off Broadway production of “The Pride,” about a fraught love triangle in 1958 and a stormy gay relationship in the present day, will extend for an additional week to March 28 because of audience demand, the producers announced on Wednesday.

Starring Hugh Dancy and Ben Whishaw and directed by Joe Mantello, “The Pride” opened on Tuesday to favorable-to-mixed reviews, and the producers said that the run is already 85 percent sold out. Box office business for “The Pride” on Wednesday broke the single-day ticket-sale record for the MCC Theater, the producer of the show.