Let's talk about Sue

I love this movie first and foremost.

As a young man I never would have thought about this, but as an adult who's lived in the big city at one point, I have to mention this. First, Sue was dating Richard. That must be noted. She was on assignment and met MJCD on this trip, then decided to make a pass at him on the beach and they kiss. So she effectively forgot about Richard and cheated on him with MJCD.

She then returns to the U.S. with MJCD, presumably for the story to continue, but really it was for her own ends. She was confused and wanted to continue seeing (and presumably screwing) MJCD. Richard seems to have some reservations based on his tone about MJCD but goes along with it, even at dinner. Richard, trying to save face, does act like a total dueche at the dinner, and got owned by Dundee. Then Sue has the nerve to defend him in the cab and tell Dundee that she loves Richard.

Richard is notably absent at the party with the cocaine, as well as when they seem to be out on the town when he is about to get mugged. Once he saves her, again, she walks up to him and kisses him (and I assume they finish the night together). She is effectively cheating on Richard again and Dundee at the same time.

Richard asks for her hand in marriage despite all of this, and she accepts. Ridiculous in and of itself, she is not thinking about Richard when she accepts and still stares at MJCD.

Then she ups and leaves Richard altogether.

I get that minds and hearts change. And Richard wasn't altogether wonderful. But this is slutty behavior at its finest.