And then Kris Jenner, Khloé, and Kim all returned the compliment by tweeting how much they love Millie.
And it's safe to say that Millie well and truly lost her mind. Bible.
Well, the friendship has only strengthened this week after Millie tweeted that she desperately wanted Kourtney to "shake her salad."
For those of you less familiar with Keeping Up With the Kardashians than Millie, the family eat big plastic bowls of salad on the show a lot. And before eating them, they shake the shit out of the bowl to spread the dressing around, like this.
Despite not @ing any of the family in the tweet, Kim saw Millie's message and responded saying that she could make the dream a reality.
And Millie was, of course, thrilled.
And then Kourtney herself confirmed the plans too, sharing this on her Instagram story.