Andrew Johnston resists the urge to rugby tackle the Brothers Grime, and keeps his notepad on view at all times

Jedward may be many things (‘odious little sh*ts’, according to Labour election candidate Stuart MacLennan, who lost his job for ranting about them online), but quitters they are not.

Last month, the bequiffed X Factor phenomenon were dropped by Sony when their debut single ‘only’ got to number two in the charts. The very next day, Jedward signed to Universal. The irrepressible Grimes brothers have also been busy filming ads for Abrakebabra and Shake n’ Vac. ‘It was like being in a movie,’ gushed one or the other. (Like Ant and Dec, it’s hard to tell who’s who.)

Now, following gigs in Dublin and Derry, the Jedward circus arrives in Belfast. The Waterfront is sold out, which is a feat not even million-selling rock legends Yes could pull off at the same venue recently.

The Dublin duo’s young fans wave flags, banners and body parts at the stage, while some sport ‘Jed Heads’ – cardboard mock-ups of the twins’ famous hairstyle, available for £3 at the merchandise stand. Disgruntled parents, the odd loner and a journalist (that’ll be me) make up the numbers. I ensure my notebook is visible at all times, so no one thinks I’m here to ogle 15-year-old girls.

DJ Liam McKenna (an ex-member of Irish boy band Six), and the Act One Dance Troupe (a gaggle of girls from Dublin) are on first, thumping through a mish-mash of Justin Timberlake, Lady GaGa and, bizarrely, Drowning Pool.

The nu-metal growlers are probably the most terrifying thing most of these kids have ever heard. For me, that’ll be the cacophony of blood-curdling screams that greets the entrance of John and Edward. The poor man’s Bros run to the stage from the back of the hall, to the strains of the Rocky theme. I’m within a couple of feet of Edward, but resist the urge to rugby-tackle him to the ground.

It is well established that Jedward can’t sing, can’t dance and look awful. But 2,235 bums on seats can’t be wrong, and the brothers have enough of Louis Walsh’s money behind them to ensure a super-slick, crowd-pleasing show with plenty of costume changes. John and Edward bounce around to ‘Rock DJ’, ‘Oops!… I Did It Again’, the Ghostbusters theme and their medley of ‘Under Pressure’ and ‘Ice Ice Baby’ (twice).

Their vocals are so low in the mix it’s like karaoke in reverse, and the between-song banter is a strange blend of gibberish and bravado. But the weirdest moment during the 60-minute set is when Jedward play – sorry, bounce around to – ‘All the Small Things’ by Blink-182. If nothing else, it proves that the line between crap punk and crap pop no longer exists.

Perhaps we should expect more from grown men. After all, Angus Young was the same age as John and Edward – 18 – when he formed AC/DC. But in 2010 the public gets what the public wants, and after Belfast they’re getting it in Dungannon, Omagh, Waterford, Killarney and Cork – all sold out. Scary stuff, but who ya gonna call?

Andrew Johnston