"Basically, there's a hardcore fan base in Britain and Ireland all connected up on this massive network, so someone will say: ‘Oooh, they're on their way!' and by the time we get there, we're surrounded...
"They track us everywhere. It's got so bad at airports that we have to hide in the special VIP bit.
"And if anyone in this room went on Twitter right now and said: ‘We're doing a photoshoot today,' there'd be hundreds of them here in half an hour, waiting outside and pretending to be cleaners, journalists, delivery men — anything to get close to us. They're properly hardcore."
Goodness! So who could these poor beleaguered chaps be? Oscar-winning film stars, international heartthrobs, Olympic athletes?
Er, no — "Although our hair's a bit like the Olympic flame, don't you think?"
Together, John and Edward Grimes are Jedward, the 19-year-old twins from Dublin who shot to fame in The X Factor 2009 — despite being unable to sing, dance nor, it now transpires, finish a sentence without constantly talking over each other in silly faux American accents and bobbing all over the place in excitement.
Their routines consisted of jumping about in silver suits, singing flat and out of time, and being supremely irritating and breathtakingly (we all thought) over-confident.
Amazingly, despite countless "We hate Jedward" Facebook groups and being dismissed by Simon Cowell as "vile little creatures who would step on their mother's head to have a hit", they made it to the semi-finals, coming sixth. Then everyone thought that'd be that.
But instead, they left school early and, after a stint on the official X Factor tour, did their own tour of Britain and Ireland, performing their truly awful song-and-dance routines in shopping centres and village halls and at fetes, parties and civic centres.
And as the X Factor's actual victors wilted in the spotlight (2009 winner Joe McElderry was dropped by his record label in April 2011, while last year's victor Matt Cardle appears to have gone very quiet of late), Jedward have gone from strength to strength.
Having the last laugh
They've popped up everywhere you look, raking in more than £3 million (Dh11 million) over the past 18 months — "And that's an old, old amount, because even when we're asleep it's always rising" — and having the last laugh. Or they would if they'd just stop talking for a minute.
Over the past year and a half they have starred in their own reality show, advertised everything from Shake 'n' Vac to Nintendo DS, represented Ireland in the Eurovision Song Contest (they came a very respectable eighth) and now have a chat show, a documentary, a European tour, a new album and a rumoured £1 million appearance on Celebrity Big Brother in the pipeline.
And they're the new celebrity ambassadors for a free summer athletics scheme for children (both were obsessive runners and Olympic wannabes before The X Factor).
They have also met everyone from Paul McCartney ("We talked about trainers and got him to sign lots of Beatles albums") and Lady Gaga ("Everyone says we're like Lady Gaga — or at least if she had a baby, it'd look like us!") to Tony Blair and Barack Obama.
"Guess what? Obama was in Dublin and there was Daniel Day Lewis and all these big actors and important people, and he skipped the lot and walked straight over to us and asked: ‘What's this whole Jedward thing about then?' and shook our hands."
So what on earth did they talk about with the world's most powerful man — international politics, the global recession, Afghanistan?
"No, silly! We talked about Justin Bieber and Miley Cyrus and all the greats.
"And if he could arrange it for us to go on The Oprah Winfrey Show.
"And we talked to his wife about her hair.
"She was lovely and he was really noble. And he's really, really focused when he's talking to you. He's not really like a president, he's more like a celebrity — so cool."
And Tony Blair. What was he like?
"I don't think we've met him."
But didn't they meet him on The Late Late Show on TV in Ireland? At the time, much was made of it being a rather undignified coupling for Blair.
"Oh, yes! We forgot! Well, the difference... Tony Blair is white and Obama's black, but that's cool. And Blair wanted to get a picture with us, which was cool. And how cool to have met two massive world leaders."
It must all feel light years from life in Co Kildare where they grew up with mum Susanna, a secondary school teacher, dad John, a computer expert, and elder brother Kevin, a law student and aspiring model. They were eight when they started gelling their hair into an embryonic version of today's ridiculous quiffs ("John went first and I copied when I saw how good it looked"), idolised pop stars like Justin Timberlake and the boyband Backstreet Boys and dreamed of fame.
For some strange reason, adulation from the opposite sex was initially in short supply.
"Every Valentine's Day we'd buy loads of cards and roses and give them to all the girls."
And did they get loads back?
Chatting to Jedward is like being mown down by a juggernaut. It/they are relentless Ϡthey never stop chatting (much of it rubbish), jumping about, preening themselves in the mirror, practising bizarre robotic dance moves, speaking in odd accents, telling me how amazing their new album's going to be and gushing about the brilliance of their Aviva Startrack summer athletics scheme for children.
They are also extraordinarily close, even for twins. As they have their make-up done, one will very delicately remove a stray hair from the other's cheekbone or wipe away a bit of mascara. Every sentence is started by one, finished by the other. They claim to fancy all the same girls ("Sweet pretty ones, not the ones who are supposed to be hot") and admit to never having had a serious relationship.
So do they spend much time apart?
Silence. Followed by: "What do you mean?"
Well, you know, time apart from each other.
"No! Occasionally one of us might go to the shop to buy some sweets..."
"But we'd go in disguise."
What sort of disguise?
"I go as Harry Potter— I have glasses and a wand and everything..." says John. Or is it Edward?
"And I go as Draco Malfoy," says Edward. Or is it John?
They still share a room with the beds pushed close together. "We need to talk to each other in the night. We'd have a massive phone bill otherwise."
So, barely a decade later, is fame just as they'd hoped? "Yes. We love it. It's brilliant. We're massive. Everyone in the UK knows we're Jedward; everyone across the whole of Europe has gone mad for Jedward. We get mobbed everywhere."
By whom — teeny tots?
"No way! Our fans are all ages. Loads of teenagers, loads of 15-year-olds and loads and loads and loads of girls. One person takes a photo and everyone's like: ‘Oh my God, it's Jedward!' Last night they were all singing outside our hotel in Mayfair. How cool is that?"
Don't they get fed up not being able to pop out for a packet of sweets without dressing up as Harry Potter?
"No. We don't want to do normal things any more. It's amazing being able to make someone's day by signing an autograph or posing for a picture. It's a privilege, and we'll never forget that."
And what about all the parties and falling out of nightclubs that goes with being a 21st-century celebrity?
"We don't drink or smoke, so we never ever go to parties..."
"And we're not like all those people who say they don't when really they do. We've never ever drunk or smoked. I think it would totally affect us. It would make us, well, I don't know."
Indeed. The thought of a chemically stimulated Jedward beggars belief. Their chat is startling enough.
For example, ask them about former Harrods owner Mohammad Al Fayed, who's tipped to be on Celebrity Big Brother with them, and it's: "He sounds brilliant. We're going to ask him how to set up our own shop."
Or whether — as is widely rumoured — they are both still virgins, and the pink-faced response is: "We love the Madonna song Like A Virgin, but that wasn't really about sex, was it?"
Or even money: "We don't really care about that. In 20 years we'll check our bank account, but for now we only need enough to spend on cool shoes and cool presents."
So, finally, what if all this adulation came to a grinding halt?
"We'd build a huge empire — our own TV shows, our own magazines, our own company: Jedworld! And we're already saving all our outfits to auction off one day like Michael Jackson...
"And our hair. Someone will want our hair, so we're saving that, too."
And with that, we're done. Which is just as well, because I'm not sure I could take any more.
Jedward is/are not as I'd expected. Yes, they are exhaustingly chatty, horribly bouncy and ridiculously over-confident. But they are also sweet and funny and innocent, even if they do talk a lot of rubbish.
So I'm a teeny bit disappointed on their behalf that, despite a naughtily indiscreet Tweet, when we leave the studio there's no one outside screaming "Jedward!" or pretending to be cleaners. I just hope for John and Edward's sake there's a big crowd outside their hotel.