Speaking of which, here's the first episode of season 3.
This episode was written to address the fact that Chase ("Alexa") got Invisalign between seasons to close the gap between her two front teeth (think Letterman but less drastic). Probably no one would notice or remember that she even had a gap, especially at streaming video resolution, but I like the idea that Nate would force her to make major cosmetic changes for the sake of their videos, and that she would actually do it.
It is true that Chase's dad thought her gap was cute. It's not true that he left. At least I hope it's not. Yikes.