What does it mean that Mr. White was "amiably desirous of preventing his son from seeing it"?

At the beginning of the short story, Mr. White and his son, Herbert, are playing a friendly game of chess on a stormy evening. Mr. White takes extreme risks during the game by placing his king in danger, which is something that his wife notices from afar. In an attempt to distract his son and prevent him from noticing his obvious mistake, Mr. White calls Herbert's attention to the strong winds outside. Jacobs writes that Mr. White was "amiably desirous of preventing his son from seeing it [his mistake]" (1). Jacobs essentially means that during their friendly, lighthearted game, Mr. White hoped that Herbert would not recognize and take advantage of his mistake. Mr. White is simply attempting to distract his son in a friendly, humorous way so that he will not lose the game. Unfortunately, Mr. White is not able to hide his mistake or distract his son, who eventually puts him in check after scanning the chessboard.