When Joker brought up the possibility of him 'snapping back' and Golden Glider's death, Hartley just glared. As far as he was concerned, Joker had no idea what he was talking about with either subject. He wasn't going to snap back.

Sure, things had gotten a bit...rockier than when he initially reformed. More ambiguous as to what side of the law he was on. He'd had a few incidents that led him to be on the run from the law, or in jail for a while, but for all his mistakes and failures, he'd legitimately been trying to be a good longer than any of the other Rogues that had reformed.

Through most of Joker's monologue after that point, Hartley just glared at him, though he noticed something out of the corner of his eye. Something that resembled a long, stretching band of...oh. A quick glance confirmed that apparently Elongated Man was here, and apparently trying something. Had Joker noticed yet?

Deciding he had to keep Joker distracted until his fellow audience member could get his outstretched body parts pulled back together, Hartley decided he had to keep Joker distracted.

"I fail to see what that story has to do with motherly love. But then, I doubt you can even fully grasp the meaning of the word."

Because he'd rather comment on that than the other things Joker had been talking about.