They are adorably cute, with grubby brown fur so soft it seems to slip through my fingers like flour. It is only when one of the nine-week-old cubs playfully grabs my arm with its teeth and squeezes with an agonising grip that I remember – this is a lion, a wild animal. These four cubs are not wild, however. They are kept in a small pen behind the Lion’s Den, a pub on a ranch in desolate countryside 75 miles south of Johannesburg. Tourists stop to pet them but most visitors do not venture over the hill, where the ranch…