She wasn't a dog - fairly cute.
My Junior Prom in high school, I took a young lady who was 21 - and she was really pretty. Also, at 16 once I got my license - I dated a girl who was 19 - and we were "close." Got really angry when I wanted to date other girls as well.
Not everyone matures at the same levels chronologically - we've all seen girls especially much more mature than those males at the very same age.
I just find it such crap when it's the female that's older than the male - while understanding that older males in fact DO take advantage of younger females.
We can see how maturity can differ even on a high school football team. Some guys are 17 going on 28. Grown men!
Maybe it's not the best idea for relationships between "teachers" and "students," but some teachers are better than others.