You've been with him since he escaped from Ra's al Ghul. He was genetically created and tortured by Ra's. He definitely has trust issues.

"You would never hurt me, would you?" Respawn said watching you get ready to leave.

Everyone thought he was dead, but in reality he was just "hiding" in his apartment, even though he went out almost always.

He liked going out with you, shopping and stuff like normal people. Even though Slade and Rose accepted him, he preferred to hide with you.