A hooray (also Hooray Benry) is in British English, an upper-class male, probably university-age or a bit older, who thinks it's amusing to be loud, and rude to social 'inferiors',and the locals, especially waitresses. (In 'Trainspotting', the book not the film, a waitress hets her revenge by putting her tampon in a Hooray's soup before she serves it to him.) They wear striped shirts and try to talk a bit deeper than normal people.
In Monty Python terms, English upper class twits - public schoolboys who turn into oiks and behave rudely, noisily and foolishly in a group at public functions rather as European players of rugby football are commonly said to comport themselves at social events. The females of the species (rarer)are Hooray Henriettas.
Prince Harry and his brother are turning into right Hooray Henrys, just like all the Windsor males.