It's not just sexual prudery that makes a novel "Victorian." The more of these novels I read (and trust me, I've read my share), the more clear it is that the heart of the matter is that hero and heroine are kept apart not by Mrs. Grundy but by paralyzing social constraints.
To demonstrate my point, I will now invent the plot of a generic "Victorian" novel.
Lydia Armstrong, who is charming and rich and has been greatly improved by her singing and drawing lessons, loves handsome, intelligent Reginald Cockerell, but she can't hint that she does so for fear of appearing forward. Besides, her parson father looks down on the upstart Cockerells, who made their small fortune in trade. Meanwhile, young Cockerell feels that his first enthusiastic courting of Lydia was awkward and unwelcome; moreover, he's been informed that she loves Bentley Rayburn, an empty-headed aristocrat who drives a mean barouche. As a result, Cockerell emigrates to Australia, and although presumed to have been shipwrecked, returns after nine years and 650 pages to discover, quite inadvertently, that Lydia has been pining for him all the while she has sat patiently sewing and providing French lessons for her numerous adoring nieces and nephews. After a few more chapters and much agonizing, he at last, awkwardly, affirms his longstanding affection. Much glee; as W. S. says, "the more delayed, delighted."
Why the heck didn't Lyddie and Reg sit down and talk things out before he left for the Antipodes?
Because frankness is impermissible; it's insufficiently "Victorian." The rules don't allow it.
Although there must be a quarter of a zillion variations on the theme, the essence remains constant. All those Lydias and all those Reginalds are kept apart by the social artifices that exalt and fetichize propriety and inhibit self-realization and pleasure.
I've been indulging these sour thoughts because I've just finished reading William Dean Howells' high-Victorian (1882) domestic novel, A Modern Instance. Howells is often described as a "realist" novelist. I suppose he is, if by realist is meant that in A Modern Instance the central figure, Bartley Hubbard, is a rotter, a gambler, and an opportunist, the hero Ben Halleck limps, and the heroine, Marcia Gaylord has a foul, jealous temper. But take away these flaws and the so-called realist novel looks typically Victorian. The crux (here come spoilers) is that the scamp Bartley marries Marcia and then deserts her. A divorce follows. Our upstanding friend Ben Halleck has loved Marcia unselfishly for many years, but he can't propose to her because he has violated the rules by loving her even in the years when she was married. Will the sanctity of wedding vows and all of western civilization come crashing down if he marries a previously-loved divorcee? Howells even goes so far as to kill off Bartley, but he still can't see his way clear to allowing any happiness to Ben and Marcia. How does the novel end? Well, it doesn't end; it just stops, with Marcia rusting in Equity, Maine, and Ben puzzling and paralyzed down in Boston.
Howells, though an American, a "realist" and an excellent craftsman, cannot resolve the dilemma he has created. He is incapable of bringing his novel to satisfying close because he is as deeply Victorian as the characters to whom he has given life.
Victorians are often called Puritans, but it was the most radical of the Puritans, John Milton, who, in the 1640s, two hundred and fifty years before Howells, first advanced the thesis that divorce should be legal and that marriages should be based not on sacrament or law but on mutual love. And although he doesn't say so, I'm sure that Milton would have been perfectly at ease if Ben Halleck and Marcia Gaylord had talked about the divorce, found their way to bed, and lit out for the territories.