Currently the episode of "One Piece" is at Episode 768 where the Strawhat pirates are still in Zou. But in the Manga chapter 848 , Pudding the fiance of Sanji, did whisper something to Monkey D Luffy and Nami in the Whole Cake Island Library that makes them really surprised.
"One Piece" Chapter 848 started in the Whole Cake Island Library where some of the crew of Big Mom is laughing at what Monkey D luffy told Big Mom that not being a Pirate King is Big Mom's fault and not Lola. Next There is a someone informing the Big Mom and her crew about an intruder inside the Treasure room. Big Mom is angered as she don't want the treasure Tamatebako that came from Fishman Island to be stolen.
Next Sanji is seen in and he is thinking about Baratie, her Nakama or friends and Pudding. After that Pudding is reminiscing what Lola told her about marriage in "One Piece" Chapter 848. Lola told her that she will be the one to decide her own marriage.
The scene went to Pedro where he is being chased by Big Mom's crew as a decoy while Brook is inside the treasure room and he defeats the guards. That's when Pudding enter the library and whisper something to Monkey D Luffy and Nami. There could be a possibility that she will leave the Whole Cake Island to prevent the marriage like what Lola did before as Pudding said goodbye to Monkey D Luffy and Name in the recent "One Piece" Manga.
If Pudding do this then what Big Mom and the Vinsmoke family agreed on will be voided thus making Sanji free. Or, Pudding might tell Big Mom to stop the marriage that will cost her own life for doing so. Right now we don't know what that whisper is all about but we just need to wait for the upcoming chapters of "One Piece" and find out more.