At first glance, I think that Digby, from the previous story “A Question of Disposal”, is a world apart from Colin Graves in this story.
Consider how Digby’s mother, Mrs. Glover, imagines him, carrying on after her death. She isn’t particularly complimentary: “He would continue driving about in hairy pullovers and gym shoes, and reading publications about motoring, and he would go on contributing to one of them – mostly paragraphs about restaurants in which he had luckily not been swindled.”
Nothing is said about Colin’s sweaters and footwear, but when he met Nathalie, he was in Paris, translating Jules Renard’s letters, so I’m guessing the motoring magazines are left for Digby’s sort.
Digby is older, too, at thirty-four. And although Colin’s age isn’t stated outright, he is nine years younger than Nathalie, who is married with two young children.
And Nathalie’s mother comments on how Colin is smart to be unmarried, as there is a tension between men and women once married.
Which suggests that she thinks of Colin as more of a boy than a man, someone in front of whom she can freely discuss the complications of marriage, hers and Nathalie’s.