Cosa diavolo sta succedendo tra le star di *The White Lotus* Aimee Lou Wood e Walton Goggins?  

(Alternatively, for a slightly more natural flow in Italian, you could also say: "Ma cosa sta succedendo tra le star di *The White Lotus* Aimee Lou Wood e Walton Goggins?")  

Both versions convey the same meaning—the first is a direct translation, while the second softens "What on earth" to "Ma cosa" ("But what"), which is a common Italian expression for surprise or disbelief.