Switch the roles. If this were a male teacher who had sex with a 14 year old girl would the outcome be the same?
If so, then what good are laws?
The outcome wouldn't be the same and shouldn't.
There is a widely accepted public policy position that female sexuality should be guarded more closely than male sexuality.
That this public policy position is not shared by everyone doesn't undermine that it has been shared by most people as far back as anybody can remember.
Those who say that this is a double standard are wrong: a double standard is two different standards for the same thing. This is two different standards for two different things.