Paedophile effect
It's when you see someone who's old enough to have a kid, but they act like they're still in elementary school. They look cute, but it's all a ploy to get you to think they're still a kid, even though they're really an adult trying to be cute.
My friend's crush is a guy who still wears a tunic and acts like he's in third grade, but he's 27.
My cousin's girlfriend is 20 and still wears a headband and acts like she's 12.
My teacher's kid is 19 and still wears a lunchbox, but she's 19 and already has a kid.