Emer Nolan observes of John Banim's The Nowlans (1825) that its "most extraordinary feature is its representation of the claustrophobic, hypersexual intensity of what might otherwise appear to be the cottage idyll of the family (small wonder that an embarrassed Banim was obliged to agree with his publisher that parts of the text were 'too warm and impure')." In the novel's primary plot, a newly-minted Catholic priest (vowed, but not yet sent out), John Nowlan, succumbs to his desire for Protestant Letty Adams, and in anguish, marries her. In its secondary plot, his sister Peggy, forced by John into a form of marriage with Letty's rakish and criminal brother, Frank, undergoes a series of Gothic plot complications (including attempted murder) before finally marrying a nice Catholic boy at the end. One could read the novel as a reappropriation of Protestant Gothic conventions about oversexed priests: John's inability to control his desires, which echoes Protestant arguments that priestly celibacy is unnatural, finally gives way after a series of chastisements that force him to acknowledge his sin--allowing him, properly scourged, to return to the priesthood at the end.
But John is hardly the novel's sole example of raging sexuality. His own father's total of three children stands in stark contrast to both Uncle Aby's wild run of illegitimate offspring and the equally eye-popping stable of Adams children, themselves augmented by babes out of wedlock. "In short, between them all, and Aby Nowlan while he lived," comments the narrator, "scarce a virtuous girl or woman could be found in the neighbourhood; and some circumstances of common attention to the same object, on the part of different members of the same family, were calculated to create a peculiar feeling of disgust towards a system of such general immorality." Nominal Catholics and nominal Protestants, male and female, indulge themselves in riots of pleasure, with an odd overtone of incestuous mixing; the hint of incest-that-isn't comes back late in the novel, when a man posing as John propositions John's sister Anty. Actual incest crops up when John's first cousin Maggy tries and fails to seduce him. Bodies mix and merge without regard to religion or marital status. Or, perhaps, gender: when an adolescent John experiences his first bender at his uncle's, he wakes up to find that his bed has been shared by "one companion, at least,--perhaps two" (33), sex unspecified. Nor is it clear, near the end of the novel, why "the drunken fellow seemed to insist on doing something that the lad would not permit" (235)--the "something" left unexplained. There's little in the way of later nineteenth-century code going on in this novel; while it's hardly pornographic, readers certainly don't have to guess what John Nowlan intends to do with Maggy when he "clasped her in his arms, and pressed his lips to hers" prior to "catching her round the waist" and departing for more private quarters (56). (Fortunately for John, a priest shows up in the nick of time.)
Banim links this promiscuity to one of the novel's key questions: are there right and wrong forms of self-discipline? We see this problem occurring in representations of domestic economy. Aby Nowlan is a terrible financial manager who destroys his estate in scenes of what the narrator calls "its mean extravagance, its vulgar riot" (40). The Adams family, by contrast, appears to be a model of self-sufficiency, feeding themselves by their own hunting and fishing and clothing themselves by their own tailoring, it's also the case that their hunting could, less politely, be dubbed "poaching," and their brewing is equally criminal. Sexual promiscuity is thus a vice relating to self-control, but doesn't map neatly onto any other form of failure: it aligns with both Aby's perverted hospitality (endless offerings of excess and debauchery) and the Adamses' religious tract-style masquerade (they appear to be an ideal Protestant household characterized by prudent budgeting, but actually use chicanery to save money). Domestic economy returns again late in the novel with the now-married John's landlords, whose bodily infirmities and household management John regards with "irresistible disgust" (151): "The whole house and its inhabitants had an air of looking better than they really were, or ought to be; and the meanness, the sturdiness, the avarice, the hard-heartedness, that produced this polish and this air, he considered as loathsome as the noise, the thumping about, the loud talking, and the endless fagging of the two little skinny Helots was brazen and vexatious" (154). Here, sex is not at all to the purpose--the problem, in one respect, is that their daughter and orphaned niece remain celibate--but the disturbance remains. The house looks decent, but only is so through excessive labor that produces a mere simulacrum of middle-class respectability, the gleam of the "polish" that conceals the actually shabby furniture. Mock-hospitality, mock-economy, mock-respectability--all of these things are further symptoms of a culture that also silently endorses erotic profligacy, male and female.
The novel's key figures for revelations of criminality, though, are not instances of in-your-face sex, but of eavesdropping and peeping. Peggy peeps at a man digging her grave and, later, at that same man's murder; her sister Anty peeps at criminals conferring with the man claiming to be her brother; Frank Adams' uncle, Mr. Long, eavesdrops on a conversation that includes the possibility of his own murder; Friar Shanaghan eavesdrops on Frank's attempt to give the pregnant Peggy an abortifacient. These instances are all associated with a properly oriented and controlled mind: Mr. Long is an honorable Protestant, while the Friar, Anty and Peggy are all devout Catholics. Although their decision-making in these instances is not always of the best (Peggy, despite the narrator's best efforts, behaves in ways that can...frustrate...the reader), their interpretations of these crucial moments are correct. In what the novel represents as a culture degraded by profligate performance, moments of truth occur only when characters believe themselves "offstage"; at the same time, these revelatory instances can only be grasped as such by characters whose identities are represented as "whole" rather than "split." Claire Connolly notes of the murder scene that it "fram[es] the violent world of nineteenth-century Ireland in the context of a concerted effort to inculcate bodily and moral restraint in the reader while at the same time inciting an absorption in lurid detail" , as Peggy cannot move (because she might be heard) but is forced to witness the entire event and its aftermath. This "restraint," however, is not obtained by her will alone, but through constant prayer; she remains sane throughout (in stark contrast to her brother John's frequent bouts of melancholia and mania) by invoking the power of God, and only a mind rightly oriented through divine grace can interpret horrific events and survive the act of interpretation. By the same token, Peggy can perform for Maggy's mother and brother, in order to avoid being murdered by them, only until Maggy does something that "threw her off her guard" (243)--to be a bad actress is almost identical with being a good woman. More playfully, the Friar, by contrast, engages in a bit of mimicry, performing the role of illiterate Catholic priest for a would-be English evangelical, then later tossing the role back in the man's face: "Put your book in your pocket, go home, and, before you next come among us, learn for what. Learn that a Catholic clergyman, as well as you, draws his religious knowledge and comforts from the word of God" (121). Whereas Peggy displays her fundamental sincerity at the moment her performance spontaneously fragments, the Friar does so by ironically appropriating and discarding Protestant stereotyping, asserting the strength of Catholic identity in the process.
It is significant, then, that John sets Peggy's plot into motion by misunderstanding what he sees. Having succumbed to his lust for Letty, he runs forth, "tearing his hair, foaming,--a maniac" (136). John's sexuality shatters his self-awareness, a fall from grace that he compounds by listening to Maggy's false claim that Frank has impregnated Peggy (137). Given that John suddenly perceived Maggy's eyes as having "a reptile kind of expression" (48) while she was seducing him, the implications are fairly clear: already destroyed by the effects of lust, John listens to the serpent and interprets the sight of "Peggy kneeling to Mr. Frank" (137) through the distorted gaze of Satan. Unlike the other peephole moments in the text, which expose the truth of criminal selves to characters whose godliness enables them to recognize evil in the first place, this scene transforms a godly act (Peggy is actually begging Frank to abandon a wicked plan) into a projection of John's own depravity. Having lost God, John loses the borders of his own self, as it were.
 Emer Nolan, Catholic Emancipations: Irish Fiction from Thomas Moore to James Joyce (Syracuse, NY: Syracuse UP, 2007), 60.
 John Banim, The Nowlans, intro. Kevin Casey (Belfast: Appletree Press, 1992), 102.
 Claire Connolly, A Cultural History of the Irish Novel, 1790-1829 (Cambridge: CUP, 2014), 197.