You're in the chippie when Usain Bolt and his entourage enter and jump to the front of the queue. Do you say anything?
Sarah Martin, performing a vague approximation of Bolt's signature flourish: "What does he do? Is it a lightning bolt?"
Stuart Murdoch: "That's more of a Bruce Forsyth sort of thing."
Chris "Beans" Geddes: "He's probably in a hurry, isn't he? Fair enough - let him order."
Murdoch: "I'm the invisible man in queues anyway. I'm used to people waltzing past me."
You join us in a secluded cranny in a restaurant five minutes' walk from Kelvingrove bandstand in the west end of Glasgow - the natural habitat, you could say with confidence, of Belle And Sebastian. Present are four of the seven members of the group - Murdoch (singer, chief strategist, long-distance runner), Martin (singer, violinist, "fairweather runner"), Geddes (keyboards, Celtic supporter) and Northern Irishman Bob Kildea (guitar, bass, sport-averse Status Quo nut). Richard Colburn (drummer and snooker ace), Dave McGowan (the new boy, also a member of Teenage Fanclub and Snowgoose) and Stevie Jackson (singer, guitarist) are absent for miscellaneous reasons including, in Colburn's case, parenting obligations.
The group have just been photographed in baking heat at the refurbished bandstand, where they will perform on July 23 as part of the opening ceremony of the Commonwealth Games. All 2100 tickets for the band's first hometown show in three and a half years sold out within five minutes of going on sale.
Now they're cornered for a grilling, a band whose lauded second album If You're Feeling Sinister sprung out of the traps with The Stars Of Track And Field.
Starter question: who's the sexiest sportsman or sportswoman of all time?
Without pausing Murdoch and Geddes chime in semi-unison: "Ennis."
"Back in the day," says the singer. "Well, I say 'back in the day' but she kept it up. I think it's beauty and strength combined - the idea that she could lift you up and throw you across the room like a javelin."
Murdoch turns to Kildea: "Bobby, have you ever fancied a sportsperson?"
The immediate reply: "George Best." "Oh yeah," says Martin, suddenly animated. "You can put me down for Best."
What was your greatest sporting achievement at school?
"The three-legged race," says Murdoch. "It was me and Peter Grassom. We didn't have speed but we had technique. And we trained, even though it was P6 so we were 11 or something. We used to tie a tie around our ankles and folk saw us: 'There they go again, whizzing across the pavement.' Come the day, we were so focused, wearing matching tracksuits, going 'one, two, one' to keep the rhythm, and we stormed it. The fast guys were trying to go faster than each other."
"What we used to do at school," recalls Kildea, "was football in Bangor leisure centre. We used to go and sign our names then we'd go up to the house and watch Rolling Stones films." He laughs loudly. "Gimme Shelter, The Stones In The Park and all that."
Who has the greatest facial hair in the history of sport?
"I did like Mark Spitz," says Murdoch. Geddes' eyes light up. "He had a moustache that he claimed made him more hydrodynamic," says the keyboard player, "and then at the next Olympic Games [in Montreal in 1976] all of the swimmers had moustaches." David Wilkie for one. "Yeah, you've got to love swimmers," says Murdoch. "How about WG Grace?"
"Classic hipster beard," says Geddes.
"Captain Webb as well," suggests Martin. "He had some good hipster facial hair."
"Who's Captain Webb?" asks Murdoch.
"He was the first guy to swim the English Channel," replies Martin, "but he drowned trying to swim across the Niagara Falls."
What was your worst sporting injury?
"I once got knocked unconscious by taking a football to the groin," says Murdoch to a chorus of "oof" and much wincing. "I knew that would make you all go 'oof'," he says.
"I taught a small child how to sail," recalls Martin, "then put him in a boat on his own and he sailed straight into my back, dislodging one of my vertebrae."
What's the best sporting anthem of all time?
"We Are The Champions," says Kildea unhesitatingly.
"There are so many," says Murdoch. "I love the Superstars theme from the 1970s [Heavy Action, written by Johnny Pearson]."
"The Booker T tune that used to be the cricket music as well, Soul Limbo," suggests Geddes.
"When you're young," says Murdoch, "you don't know it's Booker T, you just know it's the cricket song. Or the Allman Brothers, the racing, Fleetwood Mac."
"The Allman Brothers is Top Gear," points out Geddes. "Formula 1 is Fleetwood Mac."
Talk turns to the Commonwealth Games, which kick off in 11 days' time. Belle And Sebastian's enthusiasm for the city in which they formed in 1996 is well-known. How do they view the overhauling of many of Glasgow's shabbier corners ahead of the Games?
"I'm a big fan of what's going on in the city," says Murdoch. "As soon as the velodrome was built I was out there snooping around all the time - there's a good cafe - and the whole vibe in Dalmarnock. It might be different for the people who live there but it's such a changed place. There's quite a vista you get when you walk up those wide avenues now. It reminds me of Spain in the 1990s or the 2000s, Valencia or somewhere."
"Don't say that," warns Geddes. "Look where they are now."
"Seventy per cent unemployment," says Martin.
"All these nice buildings but nobody under 40 has got a job," adds Geddes.
"Fingers crossed," says Murdoch. "We're lucky we have all these great facilities. We've got all these stadia and it's good to see we're actually using them."
It transpires that none of the members of Belle And Sebastian has tickets for Games events, but at least one of them will be taking in the cycling road race. "You know last year where they tried out the route?" says Martin to her colleagues. "I was in Wagamama [on West George Street] with my pal. They went by 14 times while we ate noodles. You could see them tearing down the hill and into Nelson Mandela Place. They had to slow down going into that bend but they were doing some speed. They can't ticket it, so that's one thing I will see."
You're out running and see Mo Farah speed past an old dear with a walking stick, almost knocking her over. What do you do?
Murdoch: "I'd probably ignore the old lady and try to see how long I could keep up with Mo Farah. I like to range all over the city and occasionally I get a posse of young guys trying to keep up with me. I'd be one of those guys."
Geddes: "Like Rocky II?"
Murdoch: "Like Rocky II."
And so to the bandstand and amphitheatre. The 90-year-old venue in Kelvingrove Park was closed in 1999 and became an eyesore before Glasgow Building Preservation Trust launched a campaign to restore it, with Belle And Sebastian, Franz Ferdinand and Teenage Fanclub lending their public support. After a £2.1m upgrade the bandstand is taking bookings again.
"To quote Bob, sitting right next to me," says Murdoch, "it took for Glasgow to have an international event to get it going. That's typically Scottish - you do up your good room when you've got visitors coming round."
Apart from festivals in Italy and Spain and a short tour of the US in the autumn, the group will spend the remainder of 2014 honing their live show before releasing their ninth studio album - recorded in Atlanta earlier this year with producer Ben Allen - in January 2015. They're pondering set design, choreography and video, prompted, in part, by a comment from Neil Tennant of the Pet Shop Boys after this year's NME Awards, at which the group were honoured for their outstanding contribution to music.
"We met him in a pub in London," explains Martin. "He was really nice and he was like: 'I was at that awards thing and I was thinking they've got so many good songs, it's a shame they've only got curtains and lights.'"
"With that little phrase …" says Murdoch.
"… He changed our world," finishes Martin.
"What's he got?" asks Geddes, mildly affronted. "A guy who stands there doing nothing and a load of cardboard boxes."
"And four dancers who turn themselves into dustbins," adds Martin.
"It's a sweeping statement," says Murdoch, "but I find rock shows pretty boring. I'm getting old and I like to see exciting young bands in exciting small venues. That gets me going. But once it's a couple of thousand people you've got to ask: 'Would I love our band if I went to see them?' It makes you want to make a bit more of an effort."
Will the Kelvingrove bandstand reflect elements of this new approach to performance? "No," they reply in chorus before more laughter rocks the room, leaving the last word to Kildea. "The bandstand is the show, isn't it?"
Belle And Sebastian play the Kelvingrove Bandstand Opening Ceremony Party on July 23.