After talking with Misty, Harinder and Psymuk left her to Jay and Kason. There were some things that they needed to put into place before they could focus on getting to know their mate. The first thing they did was go to Psymuk's office so that they could talk.
Finding out that they share a soul was surprising. Even though they knew the story of the first dragon, the idea that they were the story come to life made them both uncomfortable. Psymuk thought back to the ceremony where they became soul ties. At the time, his parents were horrified that he was the soul tie of a dragon with dark magic.
They acted as if he could have chosen anyone else and been fine. At the time, he had been drawn to Harinder in a way that was undeniable. Knowing what he knew now, it made sense that he couldn't have made any other decision. A lot of the trauma from his childhood stemmed from his choice.