Do we actually know that Emmy was Cody’s teacher?

I’ve seen people say pretty often that Emmy was Cody’s teacher, or that they started getting together while she was still teaching him (or were inappropriately close before they got together).

I know there’s evidence they started dating when Cody was 18 (possibly younger) and Emmy was in her late 20s. I’ve seen the old Instagram posts people reference.

What I’m wondering is: where does the “teacher” part come from? Have Cody or Emmy ever said that themselves? Is there any evidence that she taught at a school he attended, or that she was actually his teacher?

I’m not trying to defend anyone. I’m just curious whether this is something that’s been verified or if it’s become accepted through repetition.