The particular relationship between Doflamingo and Violet according to Oda

In the SBS of volume 83, a reader asked Oda why Viola and Doflamingo called each other “Violet” and “Doffy” in Chapter 788. Oda replied that there is a deep secret behind this, but because it is a pretty adult part of the story, he could not tell the reader more.

Oda: “Why do Doflamingo and Viola call each other “Doffy” and “Violet”? Actually there is a profound setting about it, but I’m afraid I can’t tell you. I told my editor about it, though. Considering ONE PIECE is Shonen manga, I’d like to hide it since the reason is for adult audience. Dressrosa is a nation of passion, indeed!!” (E.Oda)

Now this looks so different…