was "the favourite of both parents". Alexander enjoyed a more informal relationship with his youngest son Michael and doted on his youngest daughter, Olga. Alexander was concerned that his heir-apparent, Nicholas, was too gentle and naive to become an effective Emperor. When Witte suggested that Nicholas participate in the Trans-Siberian Committee, Alexander said, “Have you ever tried to discuss anything of consequence with His Imperial Highness the Grand Duke? Don’t tell me you never noticed the Grand Duke is . . . an absolute child. His opinions are utterly childish. How could he preside over such a committee?” He was worried that Nicholas had no experiences with women and arranged for the Polish ballerina Mathilde Kschessinskaya to become his son's mistress. Even at the end of his life, he considered Nicholas a child and told him, "I can't imagine you as a fiancé – how strange and unusual!" Each summer his parents-in-law, King Christian IX and Queen Louise, held family reunions at the Danish royal palaces of Fredensborg and Bernstorff, bringing Alexander, Maria and their children to Denmark. His sister-in-law, the Princess of Wales, would come from Great Britain with some of her children, and his brother-in-law and cousin-in-law, King George I of Greece, his wife, Queen Olga, who was a first cousin of Alexander and a Romanov Grand Duchess by birth, came with their children from Athens. In contrast to the strict security observed in Russia, Alexander and Maria revelled in the relative freedom that they enjoyed in Denmark, Alexander once commenting to the Prince and Princess of Wales near the end of a visit that he envied them being able to return to a happy home in England, while he was returning to his Russian prison. In Denmark, he was able to enjoy joining his children, nephews and nieces, in muddy ponds looking for tadpoles, sneaking into his father-in-law's orchard to steal apples, and playing pranks, such as turning a water hose on the visiting King Oscar II of Sweden. Alexander had an extremely poor relationship with his brother Grand Duke Vladimir. At a restaurant, Grand Duke Vladimir had a brawl with the French actor Lucien Guitry when the latter kissed his wife, Duchess Marie of Mecklenburg-Schwerin. The prefect of St. Petersburg needed to escort Vladimir out of the restaurant. Alexander was so furious that he temporarily exiled Vladimir and his wife and threatened to exile them permanently