"Sweetie," says the Joker. "I love you. He's you, so I love him too. I don't wanna lose either of you, and I don't wanna make trouble between you the way it would if I hung around with both of you all the time. Shell and Bell got sewn up and they're just fine. If you're okay with it, and it works so you don't hate yourself afterward or anything, then I want you to."