John Lennon classic Jealous Man on Saturday.
The news of Aiden's new romance is bound to shock his ex-girlfriend, Lara Hendrickse, after the 18-year old singer called off his three-and-a-half year relationship with her only a few weeks ago.
A source to The Mirror: "They were all over each other backstage and didn't seem to care who saw them."
"He seems rather smitten with Caoife. She looks an almost spitting image of his ex - it's rather strange."
They added: "Lara may not be too happy were about the situation - he's moved on very quickly. Eyebrows have been raised."
As things seem to be hotting up between Aiden and Caoife, fellow XF hopeful Mary Byrne has dismissed reports that she is seeing Wagner Fiuza-Carillho, despite reports claiming the Brazilian singer had asked her out on a date.
Byrne told the Evening Herald: "Wagner's a lovely man but he definitely wouldn't be my cup of tea and I don't think I would be his. He likes the young women, you know!"
The 50-year old continued: "I'd go for someone around my own age or about 45, or between the two. Music is my first love and that's what I feel I'm married to now - I've no time for anything else."
Wagner has since moved out of the XF house, blaming the contestants habits and a 'funny smell' as his reason for leaving.
Maybe it's because Mary wasn't interested…