My husband told me he's quitting his job

My husband just came home and threw his backpack and told me he's done with his teaching job and he's not renewing his contract. I asked what happened. My husband has almost quit teaching a few times but he says he's done done now. What happened is he has a student we will call Hailey. Hailey gets into trouble all the time and the mom never believes him when he tells her about Hailey's behavior. Yesterday he let Hailey go to the bathroom and he gets a call from the principal asking why she was out of class vaping. Instead of going to the bathroom she was vaping on the staircase. The principal sent her back to class and emailed my husband that he would have to receive a write up because of it. Because it's his student. 30 minutes into class Hailey asked to go to the bathroom again and my husband told her no and that she would be serving detention for vaping instead of going to the bathroom. Today Hailey's mother came in demanding to speak to him and also wanting to speak to the principal because how dare a teacher tell her daughter she can't use the restroom. My husband told her he had let her go and she chose to vape in the staircase instead. Mom said "My baby would never do that." My husband and this mom had to talk to the principal and they showed a video of Hailey Vaping. The mom started saying that it wasn't her and she will always believe her daughter. Anyway how this ended was the principal trying to appease Hailey's mom and asked my husband to apologize and that he can't say no to Hailey anymore about the bathroom. My husband said he said "So if I let her go to the bathroom and she vapes I'm in trouble. If I don't let her leave my class knowing she's going to vape or do something she's not supposed to I'm still in trouble?"" The principal told my husband that this is just part of being a teacher. Also Hailey wouldn't be serving detention either. Principal completely took mom's side. My husband was ranting about how parents don't understand that their kid fucking sucks. And said Hailey sucks and she's going to be a terrible adult in a couple years because nobody hold her accountable and he's done. He's done with the principal siding with idiotic parents, he's done with parents thinking their baby can do no wrong. He's done with trying so hard to be a good teacher and getting micromanaged. He's done. I really don't think my husband should just decide to quit. Especially without asking me. He will have the whole summer to find a new job but what if he doesn't? He's mad right now and won't talk about it. He's adamant about quitting. What should I do?