Mickey is about to say no, it doesn't fix anything, of course not. But that won't help. Gabe needs to let this all out, and if Mickey is the verbal punching bag to do so, then that's what'll happen. Shoot, he'd offer a hug if he thought Gabe would accept it. (He's assuming that would be a no.)

So Mickey decides to just keep quiet and allow Gabe to say all he needs to say, shaking his head to let the boy know he's still listening.