It is a shameful thing to confess, but until recently a form of apartheid had been operating in this house. Matthew did, I know, feel terrible about it. He was racked with self-disgust. "I know, I know, and am racked with self-disgust," he said, "especially with Mandela in town. But I just can't help it."
I felt a stab of pity for him then, and recalled the time he was stabbed in the lung in Johannesburg in 1991 – an incident he never talks about, in much the same way that Smashie and Nicey never discussed their charity work. "All your sympathies were for the boy from the Alexandra township, the perpetrator of the crime. You helped him escape," I said, to reassure him.
"By God, you're absolutely right," said Matthew, springing to his feet, "so let me reiterate the new rules in this house, which must be obeyed at all times. Rule one: the junior tortoise, henceforth known as Mish, is not permitted to share the garden pen with the senior tortoise, henceforth known as Miles, at any time. Rule two: in the case of any repetition of Tuesday's fiasco when there weren't enough dried tortoise food pellets for each to have a full portion, no less than two-thirds of the remaining pellets will be given to Miles, who will also have priority when stocks of courgette are dangerously low. Rule three: if Mish continues to bang on the glass of his vivarium throughout the night without pause, the penalties will include..."
That was when I left the room quietly and went upstairs to make a phone call. When I came back down about 15 minutes later, Matthew was on to Rule 19, which grants Miles full rights to mount Mish (Miles is gay), but strictly outlaws Mish from exercising any reciprocal right.
The distinction between the two tortoises has nothing to do with colour, although I must admit that Miles is the more beautiful. He is a Hermann tortoise, whereas Mish, whom we took in as a refugee because his relentless glass-banging habits were keeping the 11-year-old boy who owned him awake at night, is a Spur-thighed tortoise. The Spur-thigh is a larger breed than the Hermann and blander to the eye. But Matthew says that the real difference between them is to do with charisma.
From the moment I saw Miles in a pet shop in Chiswick two years ago, I knew I had to have him. Matthew thought I was mad, as he so often does, but once he'd spent a few minutes with Miles, his bewilderment over my spending £600 (including vivarium and kit) abated. "There really is something special about this little fellow," he said on Miles's first night with us, while tickling him under his chin.
"He has a wit, an insouciance, a certain brio mixed with ironic detachment, that I find quite captivating." Then a pensive look crossed his face, and for a moment I thought he was going to describe Miles's shell as "a touch jejune". It turned out, however, that he was dwelling on financial details, a plumber's troubling prognosis for our boiler coinciding with me spending that £600.
Money worries aside, however, it soon became clear that Matthew adores Miles as much as both Louis and I do, and Matthew's mother is so besotted that Miles now pays her regular visits in Primrose Hill. When, last year, he went to the vet be treated for wounds to his shell inflicted by our West Highland terrier, Steptoe, the veterinary nurse described him as "the most charming and gregarious tortoise I've ever met".
It must be said that Louis and I have become very fond of Mish, too. We see him as the Frank Pickle of the tortoise world and, although that Vicar of Dibley character does have endearing traits, he does also bang on and on, which is precisely what Mish does against his vivarium. "I don't think I can stand this," was Matthew's opening remark concerning Mish when we first heard the clanking, crashing sound of tortoise shell meeting glass. And soon after that he began working on the new guidelines, the tortoise apartheid legislation. There are 37 rules; penalties for breaking them "include verbal chastisement".
Feeling that I could not in all good conscience countenance this discrimination, especially on Mr Mandela's 90th birthday, I phoned my friend Mark. I told him we had a spare tortoise going and, voilà! A new home for Mish.
I was out when Mark came to collect his new pet, but within an hour I had a text reporting that Mish had settled in wonderfully. He had, apparently, quickly formed a bond with Mark's rabbit and they were "frolicking" around the small flat, which is free from predatory terriers, so no need for the vivarium.
But when I got home, I found Matthew, not frolicking, but sitting on the sofa looking unusually morose. "Is it the tennis?" I asked. "No," said Matthew irritably, "since you ask, it is not that bloody fool Novak Djokovic going down in straight sets to the mad Russian Marat Safin, who thinks that grass is for cows."
"Well, what is it then?"
"It's Mish," said Matthew, "I am missing him dreadfully. I can't bear the silence. Do you think if I repealed all the legislation and convened a tortoise Truth and Reconciliation Commission, we could get him back?"