After practising his 80s-themed song for the second live show on Saturday, Jay sneaked backstage to seek out the judges' dressing rooms.
In a video posted to Instagram, Jay - who is being mentored by judge Simon Cowell - can be seen entering Louis' room.
But with Louis nowhere to be seen, the camera pans to the bathroom, where Jay reveals: "I really need the toilet!"
Jay captioned the video: "Don't tell Louis..." Well, the secret's already out! (Watch the video below):
Jay has been working hard with Simon on his song for this weekend and the pair were pictured discussing his performance on stage yesterday.
Commenting on the photo, he said: "Me & Dad 2 (the boss!) #TheSiAdmiral @SimonCowell! genuinely such a nice bloke! His instinct though... A real honour to be mentored by him at soundcheck yesterday."
This week, Jay praised Simon as a father-like figure. He said: "I really like Simon, he reminds me of my dad. He just gives things straight and tells it how it is.
"He told me to be myself and it gave me a lot of confidence. He's really grounded and humble. He talks a lot of sense."
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