The redhead, 65, was typically chic after the show in a crisp white shirt and black trousers, layered beneath a cosy camel dress coat.
She accessorised with a simple black clutch bag, and sported heavy eyeliner and a pale pink lip as glamorous finishing touches.
The dress plunged into a deep V neckline to tease at her cleavage to all, before cascading into a soft, semi-sheer skirt to display her leggy figure underneath.
Remaining chic from head to toe, Nicole finished her look with sky-high metallic heels and a delicate ribbon choker, which tied into a bow at her neck.
Nicole and her beau, who have a 13-year age difference, are known to keep their relationship under the radar.
She told In Style in December last year: 'I’m happy, and I’m in a relationship, and we like to keep it our own business.'And that’s it.
Gushing of her act onstage, she said after his elimination: 'For me, Dermot he has already won.
He has already won the hearts of so many people out there.
Nicole was no doubt keen to relax on Saturday night - after her act Kevin Davy White missed out on the X Factor title and was voted off, placing him in third.Clearly feeling the cold more than his girlfriend however, the Bulgarian sportsman added a chunky black scarf and huddled into his hood, as they headed inside for their intimate evening.The couple have been dating since 2015, when they were first spotted locking lips at a tournament in Australia.Attending the Brilliant Is Beautiful women’s charity gala in London on Friday, Nicole was allegedly overheard telling someone: 'This is the first time I’ve ever had a contestant and I’ve not performed with them.'I’m not going to lie, I’m gutted.But X Factor didn’t ask me to.'A source then added: 'Nicole couldn’t believe it when she was told Kevin would perform with Tokio Myers.