Aurora's decision to leave Amber City with Chris wasn't because she completely trusted him. She just realized that even living in Fairview wouldn't keep her from running into Mason.

Derek wouldn't keep Mason completely at bay.

That's just how Derek was - always watching from the sidelines, occasionally stirring things up on both sides. He'd keep Sophia happy but wouldn't fully take anyone's side. So, Aurora needed more distance.

Of course, there was another reason for going ...