You truly believe a teacher, 18 years older, who fell in love with one of his students in the 1920’s was normal?
It was unheard of.
Go back and read your history. Confederate and Union veterans were marrying 14 & 16 year old girls in their 60’s,70’s and even 80’s.
It not unheard of for men to be marrying girls from 14 years old on up in a multitude of places all through history.
Lord you see men today in their 60’s or older marrying young girls 18 or older.
You must not be much of a student of history or an observer of society in general.
My grandfather heard of it. After his wife died he married one of his former students 20 years his junior. That was in the 1930s.