This is fine.
At the end of my longish analysis of Psycho II, I included a small footnote about a scene in which Norman is required to cut a sandwich in half for Mary and has an unsolicited brush with a macabre artifact from his past. I regretted not being able to go into this scene in slightly more detail, because it unquestionably sticks out as one of the sequel's centrepieces (the two best scenes in Psycho II both involve sandwiches for some reason). It's a scene where very little happens and yet the weight of everything we understand about our slasher-cum-protagonist is visibly hinging on it. Psycho II deals extensively with the disconnect between the twentysomething Norman who regarded his housebound Mother with an idiosyncratic reverence and the fortysomething Norman who's desperate to make a clean break of it, and the overwhelming extent to which they are eternally one and the same. It's in the sandwich slicing that various facets of the past and the present are brought together in an unholy amalgamation, transforming an action as banal as taking apart a sandwich into a waking nightmare, one that's by turns cruel, comic and just plain nauseating. It's a conflict that plays out almost entirely beneath the surface, for all that actually happens is that Mary gives Norman a knife for cutting up a sandwich, a task that Norman wavers on but ultimately carries out without incident, only for both characters to be left so rattled by the unspoken tension that the sandwich goes uneaten.
If you own the Arrow Video Blu-Ray release of Psycho II, then you might have been fortunate enough to get hold of a copy with a booklet containing writings on the film by Jon Robertson, as well as excerpts from Richard Franklin's unpublished autobiography about the making of the film (although I believe this booklet was exclusive to the original pressing). Robertson does have some really neat insights into the film, including a highly appreciative analysis of the one scene I was really critical of (the scene involving the teenage lovebirds who get caught out down in the fruit cellar), so I might even be tempted to go back and reevaluate that some time. In the meantime, here's what Robertson has to say about Norman's culinary practices:
"Even the way he cuts the sandwich for Mary, sliding the blade through with an unnerving deliberacy and, rather unpleasantly, pushing down with most of his hand on one side of the bread, raises the audience's hackles. (It also poses the question: if he can't even divide a sandwich inconspicuously in polite company, what hope is there for a successful integration?)"
I hadn't noticed until Robertson pointed it out, but as Norman is slicing the sandwich his method of holding it in place is to virtually flatten one half of it with his right hand, as if purposely pinning down a writhing victim, and Franklin certainly milks the sound of the blade being scraped against the plate for all its ear-splitting worth. The way in which the top slice of the bread presses upward during the process, revealing the sandwich's meaty innards, is also pretty sickening (granted, I am a vegan, but this scene is deftly constructed to ensure that, whatever your dietary leanings, you'd never feel the inclination to put that sandwich anywhere near your mouth). It is a wonderfully repellent payoff for what effectively amounts to a fake out on the film's part (although only ostensibly so - I don't think we really expect there to be any truly ugly business quite this early on in the running time, even following on from its predecessor's example).
Despite his brutality toward the unfortunate sandwich, I maintain that the viewer's sympathies do lie with Norman throughout this sequence (as I maintain they do for much of the original film - the fact is that he's so damned lovable) and on that note I would also hesitate to describe Mary as "polite" company. Even without knowing of her nefarious intentions, there are times when her ostensible innocence borders on grotesque obtuseness; for example, she apparently fails to pick up on the telltale manner in which Norman practically dry-heaves out the word "cutlery", and persists in finding him a knife with which to bisect her sandwich. She appears to so willfully put herself in harm's way that poor Norman is up to his neck in potential tipping points (as it turns out, this is exactly what Mary is doing - her method of attack is to make herself as defenceless as possible). There's a thread of wicked comedy to Mary's almost impossible naivety, which in itself should be enough to arouse our suspicions about her from the start - having pulled that extremely ominous-looking knife out from the drawer, why does she insist on giving it to Norman anyway? Why can't she slice her own goddamned sandwich? At least she has the basic courtesy to put the knife into Norman's left hand and not his right hand (see below). It is a fascinating scene for the means by which it gets under your skin, despite the actual level of threat being fairly low - for one thing, I don't think there's a sense that Norman is especially tempted to stick the knife into Mary (there is only one very slight betrayal to the contrary - as his wayward right hand is steadying the sandwich plate, it budges it subtly in Mary's direction, so that the blade comes about an inch closer to her). As thickly as Mary lays on the ingenuousness she's not really our concern here. Our concern is rooted less in what Norman could potentially do to his latest dinner companion than it is in Norman's own apprehension of what he could potentially do. We've seen the original Psycho, so we know what he's capable of. Norman lived the original Psycho without the penny ever quite dropping, but he's been brought up to speed within the past twenty-two years and he and the viewer are now firmly on the same page. Mary is gulping down milk in what looks to be witless obliviousness, having just forced Norman to take hold of a knife that he blatantly doesn't want anywhere near. It's obvious which character we're meant to identify with here. We recognise that the mere sight of the knife hurts Norman (and that, as such, he is the truly vulnerable one in this equation) and that hurts us in turn.
The question weighing intrusively on one's mind throughout this sequence is whether or not this is intended to be the exact same knife with which Norman eviscerated Marion twenty-two years ago. Norman has already run into one familiar murder weapon whilst getting reacquainted with his family kitchen (the poisoned tea leaves he'd concealed at the back of his cupboard), so the implicit suggestion is certainly extended to us. If so, then that is beyond ghoulish, for what could be more chillingly, comically revolting than seeing Norman reunited with the instrument with which he carried out his most infamous murder (not to mention, one of the most iconic cinematic slayings, period) and being tasked with utilising it in something as thoroughly mundane as food preparation? It gets particularly grisly in the borderline surreal close-up shot where light shimmers across the blade, revealing a collection of blood stains hidden upon it, as if it were possible for this scenario to become any more stomach-churning. I joked about the hygienic implications of this in my previous piece, but even if the knife had been meticulously cleaned several times over, would you really want to eat food that had been prepared with it, knowing that had it had been inserted several times into a naked woman's torso? (My first thoughts were that the police plainly didn't do a good job raiding Norman's home and seizing evidence back in 1960, but then that's actually pretty consistent with how they're portrayed in Psycho II - check out Deputy Pool's thorough analysis of the potential crime scene when he and Sheriff Hunt go down into Norman's fruit cellar following the teen lovebird's murder. Slow but not incompetent, you say?)
Whereas the tea leaves seem content to wait passively at the back of the cupboard for Norman to stumble across them, when the knife first appears it practically leaps into frame with the frenetic energy of a dog excited to see that its master has finally returned to manor. The knives encountered early on in Psycho II have an almost cartoon-like presence (Robertson notes that "knife blades gleaming regardless of nearby light sources become something of a running gag") which imbues them with a will and a character virtually all of their own. When the knife does gleam and reveal its dirty little secret, it practically translates into a conspiratorial smile directed toward Norman, a winking reminder of their former partnership (Mary appears to have her own extrasensory connection with the knife, for she uncovers it with almost comical ease, as if she knew that it was lurking there all along, which fits in with the idea that she, being Marion's spiritual and genetic successor, has an established relationship with the world she is entering). It is not just Norman's own knife that seems determined to beguile him back into his old habits; during Toomey's attempt to bait Norman at the diner, the cake knife also gleams, as if sharing a tacit dialogue with Norman about how this confrontation could potentially go down. And yet, the very first appearance of a knife in Psycho II (outside of the truncated replay of Marion's murder) occurs so fleetingly that many fail to notice it at all, not least the characters themselves. During Norman's induction at Statler's Diner, Mary accidentally (or not) knocks over and shatters a pie plate, and amid the ruptured ruins we catch a momentary glimpse of a knife smeared with the foreboding red of pulverised berries. Norman claims responsibility for Mary's breakage, for it is entirely within his nature to do so. As Perkins said of Norman, he is very trusting and generous of spirit. But even this benevolent gesture calls to mind the darker forces in Norman's psyche, for covering up for transgressions of others was something he was well-accustomed to doing in the original film, where his resolute dedication toward clearing up his Mother's illicit debris (unwittingly in service of his own homicidal urges) brought him into escalating conflict with everyone who stopped by the Motel. The berry-coated knife might not have the gleefully demonic presence of its peers, but it gives us a gruesome pointer as to where this relationship is ultimately headed, in foreshadowing the climax where Norman and Mary come to harrowing blows over the possession of a knife, following a far messier accidental wreckage caused by Mary, for which Norman feels morbidly compelled to assume responsibility.
This is not fine.
Getting back to Robertson's observations about Norman's unusual sandwich-slicing techniques, it is entirely appropriate that what his right hand is doing should bother us more than the left. Psycho II adheres to a motif used in Hitchcock's film in which Norman's right hand is depicted as his "bad" one; in fact, so long as the knife stays firmly in Norman's left hand then it's a pretty good indicator that Mary is not in any immediate danger (his right hand's efforts to edge the blade closer to her notwithstanding). Norman cuts the sandwich and performs various other mundane tasks with his left hand because he is left-handed, as was Anthony Perkins. Mrs Bates, though, was apparently not - in the original Psycho, sharp-eyed viewers may notice that in all three sequences where Norman appears in his murderous Mother guise he invariably wields the offensive weapon with his right hand. Ergo, we can deduce that the closest Mary comes in Psycho II to being directly endangered by Norman occurs shortly before the toasted cheese sandwiches dialogue, when Norman, believing that Mother is close by and out for Mary's blood, insists on staying with her and watching over her in her sleep; while ostensibly protecting her, there is a sinister moment where Norman is steering the knife in Mary's direction and unconsciously passes it from his left hand into his right. Norman continues to keep both hands clasped against the knife at this point, which tells us that he is still teetering on the brink, although during his momentary outburst, when he calls Mary out for her dishonesty, control of the knife switches very decisively to his right hand. Inevitably, I think of Peter Walker's 1979 slasher film Schizo, with its promotional tagline, "Schizophrenia...when the left hand doesn't know who the right hand is killing." Which, needless to say, is a hideously inaccurate and insensitive definition of actual schizophrenia, but it does apply quite aptly in Norman's case.