Robbie and Fallon play a game of "Loaded Questions" which leaves the host revealing a lot more uncomfortable things about himself than his guest.
We can't even say that it started off well because he welcomed her to the stage with a handshake so bad that she stopped in her tracks and asked him what the hell that was. A slow-motion replay like this was some kind of sporting event showed just how incredibly awkward it was.
It was like Jimmy had reverted back to junior high school and he was crushing so hard on Margot and he was just blowing it with every opportunity. And Margot did not let him live it down, and she shouldn't.
She did, though, confirm that the crazy long film title she posted on her Instagram page for "Birds of Prey" was totally real. "I love a long title," she told Fallon. And it's a good thing, too, as next year she starts filming "Birds of Prey (and the Fantabulous Emancipation of One Harley Quinn)."
Already we're excited, because Harley Quinn was the one shining light in the steaming pile of turd that was the "Suicide Squad" film. If we're not going to get a solo film for the character, we'll settle for her kicking butt with some of the baddest female heroes of the DC Universe.
Not one to shy away from an unusual title, Margot also explained why "I, Tonya" had such a unique name, and it apparently was a big middle finger to some marketing executive who told the film's writer, Steven Rogers, that no title with a comma could be successful. We can't help but wonder if that executive tells this story, too.
Later, they strapped in for one of Jimmy's favorite drinking games, "Loaded Questions," and Margot got Jimmy awkwardly squirming again. The premise of this game is simple. Each drink has a question below it. You must answer the question, but you can then choose to either read that question or take the shot.
Margot's first answer was, "Also, I'm sorry to do this on Valentine's Day." Jimmy guessed that this had to do with breaking up with someone, which even she admitted was awful and she felt terrible to the point she really hoped the guy wasn't watching.
Both gave some answers that we'll just have to wonder about, though, as they decided to drink rather than reveal the question behind Margot's "Will Smith" and Jimmy's "At Howard Stern's house."
But it was definitely Jimmy who revealed way more than Margot in this game, including how he wound up kissing Michael Jordan and just how awkwardly terrible his first "date" with Kate Hudson went. Let's just say she had to leave it early to go out on a date with the man she would eventually marry, Chris Robinson.
Maybe he blew it by shaking her hand.
Both of his stories were so adorable and cringeworthy we're still laughing about them. And so is Margot.
When they talk about celebrities being just like us, this is what they really mean. It's not that they go grocery shopping and buy coffee just like us, it's that they can totally misread social cues and be giant awkward flesh monsters just like us. And that's reassuring.
Got a story or a tip for us? Email TooFab editors at email@example.com.