la menor
When a guy sees a tiny girl with a big body and thinks she's an adult, but she's still a kid. She's probably still in elementary school.
I saw la menor at the park. She looked like a grown woman, but she was still in 2nd grade.
My friend hit on la menor. He thought she was 18, but she was still in 3rd grade.
That girl at the mall was la menor. She had big tits and a big butt, but she was still in 5th grade.