Paedophile effect
It's when someone acts like they're still in grade school, but they're really an adult who's trying to look cute. They're hot, but they're also trying to trick you into thinking they're still a kid.
My friend's crush is a guy who still wears a fanny pack and acts like he's 13, but he's 27.
My teacher's kid is 20 and still wears a hoodie like it's the 90s.
My neighbor's daughter is 21 and still wears a pastel outfit like it's 2003.