She was a Joke, he'd say. Not his greatest or his best but she was a pretty funny one. What had started off as a little pet project- something to stave off the boredom during one of his inconvenient stints at Arkham -had turned into one of his most well known japes!
The Bat hated it, which made it even funnier. He couldn't see how such a promising young woman had fallen for a freak like him. He couldn't understand how she could turn to a life of crime. He couldn't bear the thought that all she'd needed was a little push. A little push that he'd been unable to stop. A little push that he'd had a hand in giving.
She was nothing to him he'd announce. Nothing at all. Just a game to play with, something he could throw about and mess around with. Something he could test. Just to see how long it took until she'd break. He'd have to kill her then, no one wants a broken toy. Maybe he'd make another one, just to prove how little he really cared.
"He doesn't love you." That's what they tell her when she ends up back in the nut house. She defends him at first, saying that they're wrong. "He does love me! He does..." It sounds more like something she's telling herself than them though. Give it a week or two, no word or rose from him and then she's cursing his name, vowing never to return. He knows this. That's why it's so amusing when she comes crawling back to him the second he's dragged back through those revolving doors.
That's why he finds that moment so strange. That moment when he's in the Batmobile being hauled back to the asylum. The moment that he worries; maybe this time her words of never coming back aren't just going to be empty promises.