Jaymi is backing Fleur to go all the way this weekend when the singer goes head-to-head with Andrea Faustini and Ben Haenow in the final.
Speaking to Reveal at Capital FM's Jingle Bell Ball, Jaymi tells us: "I want Fleur to win. I love Fleur so much. I think she's the absolute perfect popstar."
And Jaymi tells us that he's even eying up a Union J and Fleur collaboration: "Oh my life, yes! I'd die for that!"
Jaymi, and his Union J bandmates - Josh Cuthbert, George Shelley and JJ Hamblett - made their X Factor return one week ago when they performed their brand new single 'You Got It All' on stage.
"It was the most unreal experience and it just felt right being back," says Jaymi. "Ella Henderson was back as well, and it was exactly two years since we got kicked off the show."
The boys performed just before the results were announced, in which Louis Walsh's last remaining group - eight-piece boyband Stereo Kicks - were voted out of the competition.
After the emotional results show, Union J headed backstage and hung out with Louis in his dressing room, but it seems like they now have a little bone to pick with him...
Jaymi jokes: "Louis was really upset that Stereo Kicks went and I couldn't help but say, 'You didn't cry when we got eliminated! So like, what is this about?!'
"It was a bit awkward. He didn't cry when we got kicked out, so why is he crying now?!"
Speaking of Stereo Kicks, Jaymi adds: "They're amazing boys and we wished them luck for the future. It was just nice to be back, and as sad as it was for them, it felt right that we were there when they got eliminated, so we got to give them advice."
Union J first rose to fame on the show in 2012. Having made the live shows, they were mentored by Louis Walsh, and bowed out of the competition in week nine, finishing in fourth place.
Union J's new single 'You Got It All' just missed out on the Number One spot over the weekend, after Ed Sheeran's 'Thinking Out Loud' climbed back to the top of the charts. The boys are now at a respectable number two, which is their highest charting single to date.
Their second studio album of the same name is out now, and features 'You Got It All' and Top 10 hit, 'Tonight (We Live Forever)'.
You can stream Union J's new album You Got It All for free for this week by downloading MTV Trax on your smart phone - http://mtvtrax.com.
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Watch Union J's music video for 'You Got It All' below: