He's coy about whether this McFly performance will feature a little Busted, and with the newly formed McBusted's excitable dynamic, it's quite believable that Bourne and Matt Willis could just have come along for the banter.
When the supergroup announced their incarnation last month, it came as only a moderate surprise to the bands' most dedicated fans, as the concept had been successfully road tested at McFly's 10th anniversary concerts in September. A performance on Children In Need would be their official debut, singing a medley of McFly and Busted hits that succinctly reminded the country of their respective assets.
As ticket sales rocketed, their tour ballooned: one planned date at the SSE Hydro quickly became four.
Bourne, whose passion for music never faltered in the post-Busted years, is suitably excited.
"We are all really looking forward to it. What's so amazing is, it's our first time together as a supergroup and, because of the amount of people coming to see us, we're in the position to put on a special show."
The details so far are hazy, but Bourne is at least certain that McFly's Harry Judd will be drumming the whole show, no matter how much of a marathon, Max Weinberg-esque performance may be required.
"Of course he will be. He's the drummer. It's good because Busted never really had a drummer, just a session one for when we played live. So that's worked out quite well.
"At the moment, whenever we're together eating lunch or in a car going somewhere, we talk about ideas for the tour. We don't know how realistic they are; we just dream stuff up. Sooner or later we'll sit down and we'll talk about the realistic possibilities. We have 11 number one singles between us. I'd like to have a mainstay part of our setlist and a part that might change."
There is, of course, one important person missing from the McBusted line-up - original Busted member Charlie Simpson, who is reported to have accepted a tidy lump sum to allow this semi-reunion to happen without him.
"When Charlie left the band, nobody stood in his way. We wanted him to be happy. He left the band at the very height of our career, and it wasn't really mine and Matt's choice.
"We recognise that he did start the band with us and he did build the band with us. But the thing is, me and Matt have always had people asking us to do things. And we never did, because even if we wanted to, we couldn't. Because the three of us own the Busted name.
"So when we wanted to do this, for the first time, the opportunity was there with or without the name. We were going to team up with McFly, and they have a band name. It could've just been McFly play the Busted hits, you know what I mean?
"So I sat down with Charlie and said, 'look, we've got the opportunity, it's happening anyway, and we'd at least like to have our name', because, why shouldn't we have our name?
"The thing is that, it's a little bit irrelevant really, because if he wanted to come back, we haven't shut the door on him. We'd like to have him come back. I just don't think he's ready to do this yet."
When the McBusted tour kicks off next year, it will be a full decade since the bands first toured together. Bourne reckons their maturity will serve them well this time around.
"We understand the position we're in a lot more. We have a little bit of perspective. First time round, you don't know what to make of it, really. I guess we're just as excited as we were the first time, but we're calmer about it, because before we were like puppies and now we're, like, a little bit older."
Sleepovers still seem to be a regular feature for the boys, though, with Bourne often tweeting tales from the abode of McFly's Tom Fletcher (the Wedding Speech one).
He explains: "I always stay with Tom when we have an early start, because it's less cars. It's like when you've got two kids going to school, they share lifts. It's easier, isn't it?"
Fletcher's wife Giovanna is expecting their first child just two weeks before the band hit the road.
"Tom's going to want to go back at every possibility, I think, to see his baby. If it hasn't come already, it's going to be expected on the tour. So we're planning in a way that will make it as easy for him as possible, by basing ourselves in fewer places."
As pop reunions and comebacks have become thoroughly a la mode, some casual appreciators may have mistaken McBusted for another one of those. But Bourne finds any comparison between their supergroup and stars of The Big Reunion to be completely baffling.
"Me and Matt were actually asked to do that show, but we didn't feel it was the right thing for us. I think if Son Of Dork [Bourne's band after Busted] had been approached, y'know, that's more realistic. They didn't reach the height of Busted. That would be the way a band like that would come back.
"This is not the same thing. With McBusted we have full control of how we do it, and we're not getting back together under the banner of somebody else.
"And McFly have always been a band, they've been around for 10 years."
James is adamant, too, that they're not just after a quick buck. His successful career writing songs for acts like Melanie C, The Saturdays and everyone's new favourite support act The Vamps, makes it seem exceptionally unlikely there'd be any need. His love for performing, though, remained unfulfilled.
"The whole thing about this is, we're all here because we want to be. I moved to New York about 15 months ago. I'd given up. I'd made peace with the idea that being in a band was behind me, that my band days were over. I was always going to make music and release it on the internet for fun, but the idea of coming back to do this for real again has taken me by surprise."
Bourne's girlfriend Gabriela Arciero still lives in New York, in the couple's apartment. He'll be spending Christmas Stateside, but after that he will "probably be coming back to England for a while". He says, with unwavering dedication: "Where the band goes, I go."
McBusted play the SSE Hydro in Glasgow in April and May.