I think that girls are still seen to be weak & in greater need of protection than boys are, regarldless of their age.
When one reads about a case like this (male teacher, female student) the publics reactions is “That poor sweet innocent darling. There is no way she could have been a willing participant - she’s been terribly victimized and scarred for life!”
When the roles are reversed the assumption is “Well, he’s a boy. Dern horn-dog knew what he was gitting into. Good for him, I say! Poor damn fool teacher just couldn’t resist him.”
Regardless of the ages, the perception is that the female is weaker & the male has more control.