Once upon a time there were three children. Their names were Matthew, Jessica and David, but they tended to go by Matt, Jess and Dave. Initially, they led fairly different lives and didn't have much in common, except that they were all in Australia.
At some point, however, they found themselves all living in the affluent East of Melbourne, in the same street. It was the best street in the best suburb in the best city in the best country in the world, but the street was very long, and their houses were the three worst houses in it, so it wasn't as great as it sounds.
Nevertheless, they began to see each other around and their parents, all being new to the area, got to know each other. It was only a matter of time before the children got to know each other, too.
Matt, Jess and Dave were quite close together in age and place of residence, so, even though they all went to different schools, they often ended up spending their afternoons and weekends relaxing together. They usually met up at Dave's, since his house was between Jess's and Matt's and he had a cool shed in the back yard, which felt very far away from parents, siblings and homework.
Dave was an inquisitive little fellow, and loved to tell the others about things he'd learned recently. He would tell them about art, cultural events, history, science... whatever he happened to have come across recently. They in turn would mostly respond by telling jokes and laughing about all of it. Dave didn't mind, though, because he enjoyed ridiculing the things he talked about, too; that was the other thing they had in common.
Pretty soon, Jess and Matt began to share the things they were interested in, as well. Sometimes they ended up making fun of each other, as children often do (for example, Dave had not been able to take Jess's passion for Riverdance seriously at all and often joked about how dumb it was, and Jess would loudly groan at Matt repeatedly sharing the same two sporting facts), but it was mostly in jest. On the whole, they enjoyed learning from each other, sharing their joys and fooling around. They were becoming friends.
On one afternoon, Dave was telling Matt and Jess about how bodies are embalmed before open-casket funerals. He had been looking into what happened to bodies after death, and embalming had struck him as one of the most unpleasant things in common practice. Naturally, that was the one he most wanted to share with his newfound friends.
Jess was finding the whole discussion thoroughly unpleasant and felt moved to question what kind of person would voluntarily become an embalmer. She was pretty grossed out just from hearing about it.
"Oh, they're definitely serial killers or something," Dave said. "It's like, someone comes up to you and says, 'I've got a disgusting job for you. It's gonna pay really badly. Would you like to do it?'"
"Do I get to be alone with dead bodies?" Jess responded, managing briefly to appear genuinely intrigued by the idea, before succumbing to giggles.
After some more hypothesising about the mental states of funeral directors and embalmers (especially embalmers), Dave went on to describe how the insides were sucked out and replaced with formaldehyde. "Then the anus and vagina are often stuffed to prevent leakage." He looked at his friends' disbelieving stares. "I'm not kidding. This is straight from a funeral website."
Jess looked like she was about to cry.
Matt's eyebrows were raised. "So, this is what happens for open caskets. Why is anyone doing that? The next time you see an open casket, next time you watch My Girl... Macaulay Culkin really went through a whole lot for this role."
This helped lighten Jess's mood a little bit and she wheezed with laughter. "They stuffed his vagina!"
This was the conversation that made them realise they enjoyed creeping each other out, and they soon began to seek out gross or unsettling facts and stories to share with the others. Dave and Jess openly enjoyed doing this from time to time, but Matt claimed that he never did it intentionally. The other two found this difficult to believe, as he sometimes told them about serial killers or presented them with disturbing unsolved mysteries and was then (somehow) surprised by their reactions, even though he was easily upset by such stories.
Jess quickly realised that, while she saw them just as creepy stories, Matt was much more aware that the people involved were real and, although he was normally quite talkative, he said very little when Dave or Jess told him about murders and tragedies.
In next to no time, Jess began to playfully tease the other two, both when they were trying to tell her something and when she was supposed to be "teaching" them. One of her favourite running gags was that Matt was really old compared to her and Dave, even though there was barely more than a year between them. She would also go on about how tiny Dave was, which was perhaps a bit more accurate; he was pretty small, and always had been, although she sometimes made it sound like he was the size of a toddler, which was a slight exaggeration.
As they got to know each other better, she found new things to tease them about and in time, they began to join in, making fun of each other for things that were, at best, vaguely based in fact.