Cheryl Cole has teased fans by posting a Throwback Thursday picture on Instagram. The singer took to the social networking site to upload a snapshot that shows her sitting next to Simon Cowell on The X Factor. Cheryl, who has been rumoured to be making a return to the show, remained coy about her reason for sharing the photo, simply accompanying it with the hashtag "Tbt". But it has fuelled speculation that Simon has convinced her to come back on board the ITV show. It comes after Nicole Scherzinger confirmed that she has decided not to return for the next series.