Bimbo alert.
Yes, the girl is an idiot, but that doesn’t excuse the teacher’s behavior.
She’s a child, not a bimbo. A 14 year old child who was most likely ‘selected’ by the perv as one vulnerable and in need of parental support or presence and not getting it. So he starts the ‘grooming’ process by pretending to listen and care when she talks about what’s going on at home etc.
When picking victims, they don’t usually pick the smartest and most well adjusted. They prey upon the the unsure, the kid who chews their fingers or hair, more likely to be fatherless, etc. The kid who most needs a friend - and they become that “friend”.