Last Night's Viewing: Natural World, BBC2Sun, Sex and Suspicious Parents, BBC3

If you happen to be one of the millions of people who've watched that video clip of a slow loris being tickled, its arms raised in the air in apparently blissful compliance, you may have thought to yourself, "I'd love to get one of those." Here's why you shouldn't – all arguments courtesy of BBC2's eye-opening film about the animal, possibly the first ever Natural World documentary to open with a wobbly YouTube clip of an endangered species getting a body rub on someone's duvet. Let's start with the eyes, since they are the key to the slow loris's captivating cuteness (when I looked, 9,135,798 people had watched that video and only 1,237 disliked it). Large, liquid and perfectly framed to hot-wire our inbuilt susceptibility to neonates, the slow loris's eyes are also very well adapted for hunting in the dark. The slow loris, it turns out, isn't a lethargic vegetarian nibbling at flowers. It will eat pretty much anything that it can catch, including millipedes, lizards and venomous spiders. Feeding time, I can tell you, is not going to be pretty, unless you like the sight of an arachnid limb sticking sideways out of your pet's mouth, like a stray Twiglet.

That diet leads on to reason number two. The slow loris is venomous itself. When it performs its very cutest gesture, covering its eyes with its tiny furry arms when alarmed, it's actually harvesting brachial oil from its armpits that it mixes with its own saliva to create a toxin. Anna Nekaris, whose studies into the loris formed the basis of last night's film, believes it uses it as an insect repellent and carnivore deterrent. She certainly demonstrated that it can kill leeches and make a sun bear think thrice about lunch, and she was also able to testify, from painful personal experience, to its capacity to prevent injuries healing. After she was bitten on the thumb by a loris, the resulting wound took weeks to heal. Slow lorises smell bad, as well, so unless you plan to shampoo them regularly you'll have a pungent pet.

The bite, incidentally, leads on to reason number three. Because slow lorises are YouTube naturals, there's a big demand for them as pets. Since the dealers don't want to be bitten, they crudely clip their teeth with pliers or nail clippers, a clumsy procedure that effectively leaves the animal maimed and means that it can't be reintroduced to the wild even if it's rescued from the illegal animal trade. And, on its way to providing you with a fluffy but malodorous conversation piece, it will pass through a trading-chain of considerable cruelty, as Nekaris proved by wiring herself up with a hidden camera and visiting one of Jakarta's biggest animal markets. After she got to 23 under-the-counter lorises, she became too upset to carry on. So don't get a loris... and you might even think about clicking the dislike button on that very sweet video.

I wish there was a dislike button for television, though my thumb would probably have ended up raw after Sun, Sex and Suspicious Parents, one of BBC3's more obnoxious offerings. It's a kind of natural history series itself, in which holidaying teenagers play the beasts while their parents take the part of the film-makers, concealed in a hide somewhere so as to capture their subjects' natural behaviour in the wild. Last night, Sophie's Jehovah's Witness parents got a crash course in her distance from the tenets of the faith and Ronnie's mum and dad discovered that he appears to be a serial self-exposer. The phrase that keeps coming into your head is "Have they no shame?", less because of what the children do than because of their parents' creepy stalking. It ended with confected scenes of hugs and learning and it made me want to spew like an 18-year-old at the end of a seven-hour bar crawl.