The Albert Square legend seemed rattled in tonight's second episode as her jilted fiancé John threatened to reveal something to Phil Mitchell that she would rather keep hidden.
As they argued over the cancelled wedding, John ranted: "Don't you dare walk away from me. I picked you up, I made you… You were nothing, you were nobody. Does he know, your friend? Does he know your dirty little secret, eh?"
Sharon replied: "No, and he ain't gonna" - but with this being soapland, that could be wishful thinking!
Letitia Dean, who plays Sharon, also hinted at a forthcoming revelation in her recent Daybreak interview, saying: "There's something that comes out later, that's happened to her in the States…"
Whether the two are linked remains to be seen - but can you guess at what Sharon's secret might be?
Share your theories on Sharon's secret below!