So, the dad fucked up, but he's mostly fine. Not the most decisive of adults, but I've seen worse. The mother is just... Well, she's an immature idiot that wants everyone to do everything for her and then thank her for being such a good girl.
Now, the teacher? Man, the teacher is an actual piece of shit. He's manipulative, selfish, and is perfectly willing to ruin the life of a teenage girl just to get together with her mom because he knows that the mom is an easy prey. Who knows, maybe he's a sociopath and everything.