It is more:
She is fit, therefore anybody (presumably of any age) would WANT to have sex with her, therefore her actions cannot be considered predatory. :nono:
It is deemed 'okay' (phwooar, lucky bugger, etc) in these posters' ill-thought opinions, purely because she is fit.
If it were a male teacher and a 13 year old girl, they'd consider it predatory and outrageous.
If it were a make teacher and a 13 year old boy, they'd consider it still worse...