I'm not the first person to notice Kay - in fact, I was alerted to her when one of the Pickford Brothers - they of Plok and Wetrix - linked to her videos on Facebook. She's even appeared on TV with Harry Hill, and boasts a considerable 19,000 subscribers.
As the title of her channel implies, Kay presents cooking videos - introducing them with a screech of "Hiiiiiii people!" - all filmed by Lee, who usually makes an appearance at the end to do a taste test. Unless Kay deems there's no point "because everybody already knows what chicken tastes like".
Typically, Kay will front her videos wearing either an Iron Maiden t-shirt (she professes not to be a fan of the band - she just likes the shirts), or, for some reason, a Soul Reaver: Legacy of Kain shirt. Seemingly without even trying - she started making her videos at Lee's suggestion, simply because she enjoyed cooking - Kay has become a bona-fide icon.
Unlike other YouTube channels, where everything is filtered and stylised, and posed, and polished, and strives to look professional, Kay and Lee do none of this. For me, that is precisely their appeal; they're an antidote to everything we've come to expect from YouTube. And I love their videos un-ironically.
Fake News has become a much overused and abused term. I am far more bothered by the fakeness we see on social media - a fakeness so fake you can almost smell it.
We've all been guilty of making our lives seem more impressive than they are - heck, I only joined Facebook to show-off to a former schoolmate after I went for a drink with him, and he spent the whole time telling me about his amazing life, and how much sex he had while working as a holiday rep.
But kids are under enough pressure without raising the bar to think they have to live like their favourite YouTubers. When I've watched videos by some of those vloggers, I despair - because they're so painfully artificial, and painfully unobtainable.
Consequently, the thing I like about Kay and Lee is that they're real. Their videos are entirely unfiltered. There's no pretending to be anything other than themselves. They make no apologies for who they are.
The camerawork is terrible, the lighting is basic, and Kay's recipes fail frequently - but she puts them up regardless. Once a week she'll shoot a "piss-take" video, where she'll make, say, a cup of tea, but for the most part they're indistinguishable from the supposedly non-piss-take videos where she makes, for example, chips, peas and Spam, or bacon and chicken (ingredients: bacon and chicken).
Admittedly, they're only showing what they want their viewers to see - and, certainly, if some of the comments on their videos are to be believed, there are a least one or two skeletons in Kay's closet that she doesn't choose to discuss online (and why should she?) - but in an age where too much of everything is pretend, it feels refreshingly unfiltered and unvarnished.
Equally, in the vast majority of Lee's vlogs absolutely nothing happens. Whereas most vloggers will go to extreme lengths to show you how perfect their life is, taking soft-focus shots of flat whites and sunsets, Lee wakes up, hangs around the house or goes to see his mates. He shows you what he's having for his tea and his supper, he takes Ziggy the dog for a walk, and apologises for not yet uploading his latest Let's Play video.
He ends every video in bed, with a rambling recap of what we've just watched... or another rambling apology for the lack of what he did. Or because his let's play video failed to finish rendering.
Somehow, it's endearing and compelling when it should be really boring. And it's endearing and compelling because it's real in a climate - and on a platform - where so little is real.
Inevitably, because many people are awful, Kay and Lee have come in for some grief over the last few months. Rather than just let them be to do what they enjoy, one relatively low-subscriber YouTube channel launched a campaign to "expose" Kay, which was jumped upon by a chattering army of trolls.
In behaviour that bordered on stalking, the host of the channel even visited Kay's home - travelling all the way from the USA - to try to "marry her", give her some gifts, and attempt to uncover the truth about allegations that had been made by someone claiming to be Lee's ex-girlfriend (example: she alleged that Kay was fired from her job as a lollypop lady because she did a poo in the street).
It was all salacious and unpleasant, and though it seemed to come to a head when Kay appeared on the channel via Skype - and was pressured into answering questions that were nobody's business but her own - there was an unmistakable sense of somebody making fun of Kay and Lee without them realising. And clearly it got to Kay, as several of her videos made references to visiting a solicitor to deal with the matter.
This was after she tried, and failed, to fight fire with fire by claiming, bizarrely, that the host of the attacking channel had once "thrown a migit down the stairs".
Thing is, it's this sort of mean-spirited online behaviour which Kay and Lee are an antidote to. There's nothing malicious or mean about their videos. They're sweet and simple, and relatable. In life, I'm always far more comfortable around people who are themselves - even if they're a bit rough around the edges - than somebody who fakes being all sunshine and rainbows. On some deep-rooted instinctive level, we evolved not to trust these people. At least when somebody is unapologetically themselves we know what we're dealing with.
Watch a video by Fun For Louis or Zoella, or the wretched Saccone-Jolys, and you're presented with perfect people showing off their carefully cultivated lives of unobtainable perfection. Who are they really?! We don't ever get to know.
Lee and Kay are a soft target, when there are people out there far more deserving of scorn.
I don't care if Kay is a sloppy cook who never does second takes. I'm not interested in seeing Lee showing off on a jet ski, or hanging out with beautiful people who never take their eyes off their own cameras. Their appeal is how grounded they are in a normal life, in rainy, miserable, Sheffield.
Certainly I despair that their success has - with a depressing inevitability - seen them targeted by miserable idiots.
But in making fun of Lee and Kay they're making fun of millions of regular people who can't afford to fanny around in the Caribbean, and who don't have enormous houses in Brighton, full of fairy lights, and huge metal initials of their name.
I mean, heck, Lee and Kay are no different from so many working class people. Kay reminds me of my mum. Lee reminds me of when I was a teenager. If I'd vlogged my life when I was 16 (although, Lee is actually 23...) there wouldn't have been much going on either. A regular dinner for me back then was boil-in-the-bag mince.
I just wish there were more people on YouTube like them. I wish more YouTubers would risk stripping away the gloss, and present themselves as they really are. Sometimes we don't want aspirational - we just want to see our lives reflected.
Runny meatballs and Spam fritters and all.