But they also sat down with Jimmy Fallon to talk about the show, and Jimmy wanted to talk about one scene in particular.
We learned that it was Millie's first ever kiss.
And it turns out pretty much nobody on set made her feel better about it.
But the most teasing came from their castmates, Gaten Matarazzo and Caleb McLaughlin, who play Dustin and Lucas.
And it turned out Millie wasn't a huge fan of kissing, tbh.