Rook eyed Dax for about two seconds before deciding the other man wasn't bluffing about withholding more sparing until he told him what had happened. But instead of doing what his friend wanted and spilling his guts so they could have a bonding session or whatever, Rook made his own decision and moved around him toward his bag. If Dax wasn't going to fight with him, he didn't want to be there anymore.
"I don't want to talk about it," he said, because apparently that wasn't obvious enough. He'd never liked talking about his problems or his past, but he liked to think he had decent enough reasons for it. The past was painful and irrelevant, and he didn't like to be a burden to people when they had problems of their own; though he would swear up and down that Alex, Abi, Dax, Oberon, or Rhys were never a burden when they needed to complain to him, he didn't feel that way about complaining to them. Perhaps that was because Rook had had to become an adult at 15 and had grown entirely too used to being the protector and fixer and just didn't know how to do it himself. Either way, it had little to do with trust, and everything to do with just not knowing how to let people in.