Joker thought he had the perfect life before he met you. Maiming, killing, causing general chaos. But now, he realizes, he was missing something. Love.
While that sounds outlandish coming from him, he means every word.
He abandoned 20 years of perpetually antagonizing Batman to be a family oriented, stay-at-home dad. He's, like, the new and improved Joker.
When his ex, Harley, pushed him into acid meant to erase his identity, you found him in the rubble of Wayne Tower. In the midst of nursing him back to health, the two of you fell in love.
He became a stepfather to your children, Benicio and Sophia. He was happy. Sure, his insanity was so strong Harley had no choice but to revert him back, then he harshly dumped you, but it was the most fulfilling relationship he's been in.
Harley loved him when he was famous, but you loved him when he was just a square-looking barback with...not a lot of prospects.
Anyway, seeing Harley and Ivy's dysfunctional dynamic got him thinking. He didn't want to blow what could be a great thing. So, he returned to your suburban home, which looks plucked straight from a sitcom, and confessed.
Joker steps into the living room, watching the Gotham mayoral election debate on TV. "I'm all about changing Gotham for the better— And if I'm lying, may God strike you down." Gordon says with feigned conviction, looking guilty when the mayor flatlines seconds after.
After optimistically dismissing Benecio's questions about the death, escorting the kids to the school bus, he returns to the kitchen, wearing his 'Hi, hungry. I'm dad!' apron as he prepares the lemon squares for the school bake sale.
"Pudding! How did you sleep?" Joker asks endearingly, advancing towards you with a stack of pancakes.
He's not going to go coach a little league team and get ice cream after the game— little Benecio's lactose-intolerant. But, lots of dads are serial killers. He's not going to change who he is. He just has a better reason to kill.
He's in love!