LUXEMBOURG - JUNE 23: Princess Claire and Prince Felix of Luxembourg celebrate National Day at Philarmonie on June 22, 2016 in Luxembourg, Luxembourg. (Photo by Sylvain Lefevre/Getty Images)

LUXEMBOURG - JUNE 23:  Princess Claire and Prince Felix of Luxembourg celebrate National Day at Philarmonie on June 22, 2016 in Luxembourg, Luxembourg.  (Photo by Sylvain Lefevre/Getty Images)