There is a fine old tradition of distinguished literary men addressing their loved ones by animal-world pet names. Evelyn Waugh saluted Laura Herbert, the woman who became his second wife, as ‘Whiskers’. Philip Larkin’s letters to his long-term girlfriend Monica Jones are full of Beatrix Potter-style references to the scrumptious carrots that his ‘darling bun’ will have unloaded on her plate at their next meeting should wicked Mr McGregor not get there first.