"She's really one of the top three reasons that I am the person that I am and the artist that I am and that I even started making music in the first place," shared Eilish
The song rounded out Del Rey's headline show on night one of the Alabama festival
Including covers of BTS and Billie Eilish
Del Rey and Kardashian posed for photos together, despite the rumoured feud between the latter and Taylor Swift
Del Rey is due to release a country album later this year
The special one-night-only performance will take place in June
It comes after fans speculated about their recent on stage appearance at the festival
"I like to think that my memory is pretty good, but if it turns out it’s not, I won’t lose too much sleep over it"
Lana recently performed the same song during a 'Christmas at Graceland' TV special
It comes after her set over the weekend ran 13 minutes over schedule