Bruce didn't have a better way of explaining it to her. One night he had fone to sleep next to Lisa, then when he woke up he was alone and she wasn't speaking to him. Still, he wasn't in the habit of shirking responsibility, regardless of whether or not it made sense to blame himself.
"You don't need to apologize," he said. He'd told her before that her feelings were justified, and he understood where she was coming from. He wasn't sure what she meant when she said it was in the past. Was she dismissing it because time had passed? Bruce wasn't good at letting things go, and didn't really expect Lisa to be any better at it. "I've already promised a half dozen teenagers that I won't leave again. Ones that I've trained with the skills they'd need to hunt me down if I did leave." He offered a small smile. "I'm not disappearing again." He was still standing, unsure from her words if she wanted him to stay or not. Sure, he could unravel the plots of mastercriminals, but his deductive reasoning seemed to fall short when it came to making a relationship work.