Saw Once Upon A Time In Hollywood yesterday! I can get why some people might think it's a little bit long; the first two acts are a ton of character development and dialogue. But oh boy, even people that normally don't like this type of movies will absolutely love the third act. It's got everything.
If you're interested in reading the comics, Stephan Sejic (my fav artist) is doing a solo piece on the relationship between Harley and the Joker. Mostly about how she's breaking free from him, but still. I'm looking forward to that one.