Terry Graves will always love his dog Thelonious, there is no doubt about that. But it is not uncommon to find him on the streets of Meridian Cliffs pulling fruitlessly on Thelonious’s lead, shouting, “Come on! Come ON!” in what sounds like annoyance, because Thelonious is possibly the least co-operative dog that ever lived. It sometimes seems that Thelonious’s entire goal in life is to sniff where other dogs have wee-ed and then to wee on top of it: like all dogs he has a zillion more olfactory sensors than his master; the world is a miasma of complex canine urinary messages for him to detect; of urgent canine urinary conversations for him to take part in. This is why he portions out his own wee so judiciously: he needs to conserve it for spreading as widely as possible. From Terry’s point of view, of course, Thelonious’s behaviour amounts only to aggravated dawdling, and means they have to multiply all reasonable journey times by at least a factor of three.

Terry hates it when people say, cutely, “He’s only reading his wee-mails!” To say Terry is not a fan of electronic media is an understatement; he is, after all, a vinyl man with a vast collection of classic jazz albums, filed in protective tea-chests. And at age 59, he is able to remember when people didn’t self-importantly advertise every detail of their waking hours on Facebook. So Terry has opted out of the whole circus, and is pleased to boast he has never seen a hashtag. Surely the whole vain, brittle edifice of social media must eventually collapse? But it turns out that this particular fad is a hard one to sit out. Terry imagined, when he first assumed his staunch refusenik position, that his own life would be unaffected. But something strange has happened. He is out of the loop, and things have gone horribly quiet.

What Terry doesn’t suspect is that he has an enemy in his own camp. Because, as Thelonious would be glad to tell him, dogs have positively rejoiced in social media since the beginning of time. They are the ultimate joiners-in. When Terry named his Jack Russell after a keyboard jazz legend regarded as a genius of improv, he accidentally got it precisely right. Just yesterday, Thelonious sniffed a potentially classic track developing on the corner of Passchendaele Road and Blighty Crescent, under a privet hedge, on a discarded crisp packet. First a five-year-old German shepherd had laid down a decent funky double-bass groove, and then a Labradoodle (a surprisingly intelligent one) had overlaid an inviting [cymbals] tsh-tsh-tsh-tsh. Thelonious loved it. This was cool. Mentally, he listened once, listened twice. Then he sniffed, turned, niftily balanced on three legs, and by straining expertly against the lead, managed to add just enough of a classy keyboard riff before Terry dragged him away, on account of the post office being about to shut at half past twelve.

When we say dogs live in the present, we don’t realise it’s because there’s so much in the present to occupy their minds. On the average walk, Thelonious contributes to any number of ongoing conversations with dogs who have passed the same way earlier. And he has to have his wits about him. “Pawn to d4” came up recently on the lamp-post next to the pedestrian crossing, for instance, and quick as a flash, Thelonious wee-ed in response, “Knight to F6” – which was a pretty sound counter-move for someone who wasn’t even expecting to play chess. But it’s not all board games and off-the-cuff musical composition; not at all. The place where Terry lets him sniff and wee at his own pace is on a nearby hill, where he runs off the lead, and here, there’s a mound of fresh horse dung that has already inspired a kind of Poetry Slam, and a particular wooden sign-post that’s developing beautifully as a comedy workshop. Terry wonders why Thelonious lingers at this signpost quite so much, but there is honestly some extraordinary observational comedy going on in the dog world right now; it’s a golden age. “LOL” Thelonious often adds, appreciatively. At the very least he wees a series of approving “Like”s.

“How old is he now?” Mrs Clarke asked Terry the day the weeing chess tournament broke out. Terry and she had bumped into one another on the blustery undercliff walk, and then fallen into step for a while.

Mrs Clarke knows Terry and Thelonious from football; since moving to Meridian Cliffs, she has dragged her family of little girls to home matches, in the hope of integrating with the community. Thus, she has got to know other footie stalwarts such as Ravi, who owns the Flag of India restaurant, and Sarah Birkett, who knows everyone.

Mrs Clarke asking “How old is he now?” was not a surprise to Terry. In his company, she doesn’t have a lot of conversation: it’s either the club’s perilous position in the South East Hover Ferry League, or the sad advanced age of Terry’s dear little dog. Thelonious is a very popular figure on match days in his jaunty black and yellow collar-cum-bandana. Terry likes to think of him as the unofficial team mascot.

“He’s still eleven,” said Terry. “But look at him; he’s very youthful.”

At this point, on the undercliff walk, Thelonious got a whiff of a fascinating message on a pile of damp seaweed and stopped dead to give it a proper sniff. Terry and Mrs Clarke obediently stopped, too. It turned out to be a set of conflicting reviews for a new and so-called “dog-friendly” caff at nearby Rockingdean. A three-year-old cockapoo had originally awarded five stars to the place, which was patent madness, and was bound to rouse comment; unsurprisingly, subsequent reviewers had awarded one star or no stars, and then the cockapoo had ill-advisedly replied to his critics, explaining that on the day of his visit he’d been given a whole sausage, so then the discussion had turned quite nasty; quite sarcastic; quite personal. No wonder Thelonious was so absorbed. He relishes a lively debate.

“I got a lot of response to Thelonious on Twitter, by the way,” said Mrs Clarke, finally thinking of something new to say.

“Pardon?” said Terry. He stopped watching Thelonious and looked at her, puzzled. How could Thelonious be on Twitter?

“You know, when he was wearing his bandana and ran onto the pitch and you ran after him. I posted a video. It’s gone viral. Sorry, have I said something wrong?”

Terry worries about Thelonious. He worries about losing him, because let’s face it, he has never loved anyone as much as he loves this dog. And wherever they go, people ask how old Thelonious is, and ask how will he manage when Thelonious has gone, and has he thought about getting another one? You could call him Jelly-Roll, they say. Or Django. Every day, Terry expects to see further signs of Thelonious aging – is he a bit stiffer now? Is more of his muzzle grey? For a little while when he first retired from being a driving instructor, Terry used to take Thelonious to visit old people, but it became too painful. Every old person held Thelonious tightly, saying that the loss of their own dog was the worst thing that ever happened to them – and this from people who had sometimes lived through hand-to-hand combat and had survived the loss of all their loved ones, including their children. “My wife couldn’t understand it,” the old men would say. “I cried for a week.”

But if Terry worries about Thelonious, Thelonious also worries about Terry, having observed that Terry’s social life is so much poorer than his own. Terry says hello to a few people, tells them the age of his dog; and that’s it; it’s truly paltry. And now it looks as if even their outings to football might be in danger: he heard Terry arguing with a woman on the seafront about it; and Terry never argues with anyone. Thelonious, naturally reluctant to tear himself away from Sausagegate, missed some of it, but he did hear Terry saying, firmly, “Well, you won’t see us there again; I can’t believe you didn’t consult me!” and the woman saying, “But you can’t take that attitude, Terry! Not in the modern world! That boy over there’s filming us on his phone right now.”

On their way home after this blistering encounter with Mrs Clarke, they crossed the hill, and Thelonious was no sooner let off the lead than he raced to the Comedy Signpost to catch up on the latest. The thing was, a couple of weeks before, he had made his own contribution, and so far it had fallen flat. It was something he’d heard repeatedly on Radio 4 Extra with Terry, and he thought it was hilarious: “Send a tray of bread pudding to Kuala Lumpur.” He had assumed everyone would recognise the brilliance of the allusion to Tony Hancock’s The Radio Ham and award him the big paws-up. But perhaps it was too postmodern; too clever by half. Reaching the Comedy Signpost, Thelonious sniffed round it frantically, dismissing some excellent and newly minted one-liners, and was hugely relieved to detect that a ten-year-old un-neutered schnauzer had posted on top of his Kuala Lumpur Bread Pudding joke, “Is that from Tony Hancock? Clever.” And then a six-year-old lurcher had added over that, “Cool, Thelonious. Cool”, which really made his day.

Terry phoned Sarah Birkett when they got home. He phoned her on the landline, at seven in the evening. It was a risk. Years ago, the phone ringing in the house was a routine part of everyday life. Nowadays, you worry about alarming people: hearing the landline ring, they might think someone has died. But Terry needed to tell her his decision about not coming to the football any more. Secretly, of course, he also wanted to ask her opinion: had he been wrong to react so violently to the idea of Thelonious going viral when no one had even asked his permission?

Sarah not only answered the phone, she registered how upset he was and said, “Come round, bring Thelonious; I’d love you to meet Michael.” Well, wow. Terry was thrown into confusion; the idea of visiting someone in their house and meeting their new boyfriend – well, again, it was something that used to be normal, but he couldn’t remember the last time he’d done it. But by the time he and Thelonious got home again that evening, he was dizzy. An evening of laughing with an old friend, making a new friend – it was almost too much. Sarah had been supportive and sympathetic to his outrage about Mrs Clarke’s offending tweet, but she also pointed out that many people (including herself) had loved the video because Thelonious was a very popular dog; Terry should put it behind him, patch things up with Mrs Clarke, and not even think about abandoning the football. Imagine the impact on team morale if Thelonious the team mascot wasn’t there!

“Do you liked quizzes at all?” Michael said, as Terry was leaving.

And then, amazingly, Michael suggested that the three of them visit some local pubs on their various quiz nights, and see how they got on. Terry said he loved the idea. He could name all the noble gases, as it happened. He also knew the provinces of Canada, with their capitals. Sarah said that was a lot more than she did, and how about trying a pub in Newhaven the following Monday? It was as much as he could do not to burst into tears.

“You see?” Terry said happily, when they got home. “Who needs social media, eh?” He gave Thelonious his bedtime treat and then scooped him up and hugged him, holding him tight. And Thelonious – who had added a brilliant, game-changing “Bishop to H3” before they crossed the road – enthusiastically licked his nose in agreement.