TILBURG, NETHERLANDS - APRIL 27: Princess Amalia, Princess Alexia and Princess Ariane attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)
TILBURG, NETHERLANDS - APRIL 27: King Willem-Alexander, Queen Maxima, Princess Amalia, Princess Alexia and Princess Ariane attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)
TILBURG, NETHERLANDS - APRIL 27: King Willem-Alexander and Princess Amalia attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)
TILBURG, NETHERLANDS - APRIL 27: Princess Amalia and Princess Alexia attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)
TILBURG, NETHERLANDS - APRIL 27: Queen Maxima and Princess Alexia attend the King's 50th birthday during the Kingsday celebrations on April 27, 2017 in Tilburg, Netherlands. (Photo by Patrick van Katwijk/Getty Images)
