The Bleeding Love star shared a photo of the twosome posing for the camera together on her Twitter page yesterday.
The 28-year-old beauty captioned the snap: "Had a little visit with this lovely lady today @SamBaileyREAL"
What appears to be the lid of a piano and a lyrics sheet can be seen in the bottom corner of the pic, sparking rumours that Bailey could be performing one of Lewis' tracks this weekend.
This week the show is celebrating its tenth birthday, with hopefuls performing a range of songs from former X Factor stars.
Previous contestants One Direction, Olly Murs and JLS will all be on hand to perform.