But the pair found each other again and walked down the aisle in the wedding of the year in May, followed by a camera crew who filmed it all for their upcoming TV show.
And it could be the start of a new career for Cliona and fellow musician Simon.
The Tyrone talent can’t reveal any details until the deal is sealed but the laidback pair had so much fun filming From This Moment On they’d welcome another slice of reality TV.
“When Simon and I were being filmed we felt very comfortable. They were able to keep ‘us’ and how we are in real life,” says Cliona.
“There are some exciting things in the pipeline, and we’re looking at a few things that might be coming up soon. Watch this space.”
In the year of planning for their big day the couple were filmed finalising all the details from flowers to food, and admitted to their near miss.
Cliona, a former music teacher who has taken the country scene by storm since her launch in 2016 says she was too busy for love when Simon first asked her out.
“This was five years ago when he said he’d love to take me out for dinner,” says the singer.
“At the time I was so busy and not in the frame of mind for dating because I was concentrating on my career.
“When he asked me, I wasn’t ready at the time, but we laugh about it now.
“We’re best friends with so much in common and we love each other. Thank goodness he came back.”
On their big day the couple tied the knot in front of 200 guests in St Mary’s Parish Church in Tang and then partied in Kilronan Castle, where one of the most memorable moments was the first song from Simon’s singing legend dad Dan.
Even though they’d been together for three years and engaged since Christmas Eve 2020 when Simon arranged a surprise proposal on the banks of Lough Ree, Cliona says getting married has made a huge difference to her life.
Despite her success, most recently with The Dolly Songbook album and sell out tour of Dolly Parton songs she admits to moments of self-doubt.
“I feel like getting married to Simon has put me on solid ground.
“I was always not very self-assured, asking myself ‘should I do this,’ ‘am I going in the right direction with this song?’
“At times you think ‘what the hell am I doing?’ but I think everyone has those moments. Social media doesn’t show the whole story.
“I’ve always had self-doubts and not felt confident but now that we’ve made this commitment to each other and showed how happy we are and how much we feel for each other it’s definitely made a difference.
“To have your best friend and cheerleader and someone that you trust 100 per cent gives you the confidence to go on stage,” says Cliona.
The Cowboy Yodel singer also reveals the pair share the same easy-going attitude to life and gives full credit to wedding planner Corinne Claffey Concannon for making their big day happen.
The couple had initially wanted a wedding in a barn but went for a fairy tale castle setting, with a dress by designer Geraldine O’Meara who surprised them with a veil hand-stitched with their initials.
“Corinne was fantastic in bringing everything together,” says Cliona.
“Simon and I are so lackadaisical if it hadn’t been for her I don’t know what we would have got done.”
He had carried the engagement ring for six months before finding the perfect moment to propose, confiding in close friend Una Healy that he planned to pop the question.
“He’d kept the ring in his coat for six months. You can see I don’t snoop in his pockets,” says the singer.
“We were out with Una one evening and he told her he was going to propose to me, and when he did it was perfect. He is just such a romantic.”
The couple honeymooned in Nashville and took a road trip to New Orleans and Texas, as well as visiting Dollywood. Cliona’s unique voice and look has earned her comparisons to the queen of country and she couldn’t pass up the chance to visit her home turf.
“It was just great to see what Dolly Parton has built, and the Smoky Mountains of Tennessee which are so beautiful and picturesque.”
The 33-year-old is delighted their wedding plans were filmed and says they will have hours of footage to look back on.
One of the most special moments featured in the show is her walk down the aisle to Shania Twain’s You’re Still the One, the song Simon had played during his romantic wedding proposal.
“It was my make up artist who’d said to me to look at the congregation, at all the people who were there for me and Simon.
“You always hear that it seems so daunting to walk down the aisle, but I looked at everyone who was there to support us and smiled at them and I enjoyed all of it,” says Cliona.
Cliona and Simon: From This Moment On is on BBC1 on Wednesday at 10.40pm.