The teachers can’t address why someone in the class has two dads without risk of being sued. Heck the wording is vague enough you might not discuss marriage.
The ambiguity in the law is there as a feature to hush normal conversations that might otherwise happen.
Arguably, using "Mom" or "Dad", or even gendered pronouns is restricted. Of course not using these would upset the very people who wrote the laws, which is another part (beyond the enforceability) that makes them insane.
Why is an individual students parents a subject for a classroom? That is utterly bizarre and it sounds like the teacher in your hypothetical is singling out the student.
The ambiguity in the law is there as a feature to hush normal conversations that might otherwise happen.