Matt Cardle was in a relationship with 'Britain's Got Talent' star Lettice Rowbotham.
The former 'X Factor' winner was reportedly an item with the violinist - who is currently competing on Simon Cowell's talent show - and it is said she is still "besotted with him".
An insider told The Sun newspaper: "Lettice and Matt are great friends but what she likes to keep quiet is that they were a couple.
"It was quite a full-on thing and she was always talking about how sexy he was. She was besotted with him - and still is."
While the pair are still very close, it is said their commitment and ambition meant they are better off staying friends rather than trying to make a romance work.
The source added: "It didn't last long though. I think they both thought it would probably ruin their friendship. They both have an ambitious streak so it works best if they're just friends."
Lettice has worked with Matt in the past, along with Olly Murs, but insisted she has worked extremely hard to get to where she is now.
She recently said: "It does sound amazing, but those are just the best bits of 20 long years working very hard. There are very long days of gigs and travelling.
"Travelling sounds glamorous but it's not, when you're on an aeroplane for 20 hours and you have to sound check at three in the morning."

Susanna Reid isn't focused on her 'Good Morning Britain' salary.
The TV host will front ITV's new breakfast show and while there have been reports she will earn £400,000 - rather than the £1 million she was rumoured to be getting paid - she is motivated by the excitement of being part of something fresh.
She told the Daily Mirror newspaper: "We are lucky to be generously paid. But the days of million pound presenters are gone. it is nothing I have experienced.
"I am focused on the new programme. Imagine if it works? If people watch and love it, and they think they want us in their kitchen, that is the ultimate privilege and what we would love."
Susanna also revealed the team behind the show - which will launch on Monday morning (28.04.14) at 6am - are excited to get started and don't see it as a risk.
She added: "None of us have gone into this thinking, 'God what are we risking', but 'wow, let's do this and make a programme viewers will love and build on this'.
"I have always said there is room for two strong breakfast programmes. That is what we have to do, make a very strong breakfast programme that people will watch."

Rita Ora admits Calvin Harris was worried she would appear nude in 'Fifty Shades of Grey'.
The 'I Will Never Let You Down' singer - who is dating the Scottish DJ-and-producer - admits he had a meeting with her father and brother about her role in the upcoming movie, even though she never took her clothes off during filming.
Asked if she appears nude in the movie, she said: "Nope! Calvin, my dad and my brother had a group meeting to worry about it. I leave that to the main characters."
The 23-year-old star is smitten with her boyfriend and thinks he's a genius after working with him on her new single.
She said: "He gets me, so he brought out the best in me like nobody else could."
She added in an interview with Us Weekly magazine: "He wrote it in about an hour. And he writes as he takes a shower. What a genius!"

Noel and Liam Gallagher are back on speaking terms.
The two feuding brothers and former Oasis band mates - who famously fell out backstage at a show in Paris in 2009 - are said to be slowly reconciling and it is seen as a "baby step" towards an eventual reunion for the group.
A source told The Sun newspaper: "The mudslinging has stopped but it's very much baby steps for the two as Noel wants to release his second solo record at the end of the year and tour that in 2015.
"Really that leaves 2016 open for an Oasis comeback - it really doesn't seem likely that it would be this year."
There has been speculation the Britpop icons could be set for a reunion after Liam individually wrote a letter of the band's name every half an hour on Twitter, but his former Oasis and Beady Eye band mate Paul 'Bonehead' Arthurs played down the rumours.
Asking what sparked his tweets, he recently said: "Probably the fact that I texted him going, 'Meet me in the beer garden'.
"That probably rattled his cage. Maybe that. I don't know though, because I meet him every f***ing month. Maybe he's just reminiscing."
The musician then took to his own Twitter account to spell out the word "PUB".

The Wanted have told fans to "not worry" after they were threatened with a knife in Denver.
Singers Siva Kaneswaran, 25, and Jay McGuiness, 23, were threatened by a man as they left a cinema in the US, but the former boy band stars have taken to Twitter to assure fans they are fine after the scary incident.
Jay tweeted: "To reassure you, we were NOT stabbed, but a guy in Denver did pull a knife out on us- do not worry, we were lucky & we still love Denver."
Siva and Jay were outside the cinema on Wednesday night (23.04.14) when a homeless man reportedly asked them for money, then threatened them with a knife after insisting Siva hadn't offered him enough.
An insider told the Daily Mirror newspaper: "When they left the threatre they passed by a homeless man who asked for money.
"Siva gave him a few dollars, but the man asked for more and then pulled a knife on them.
"The man swung at Jay and Siva with the knife in his hand - but thankfully the two managed to get away unharmed."
According to a previous report by TMZ, the stars decided not to call the police.
The group - which also includes members Max George Tom Parker and Nathan Sykes - called time on their four-year pop career in January, releasing a statement on their website revealing they will temporarily split to "pursue personal endeavours" following their 'Word Of Mouth' shows.

Mary-Kate Olsen has bought a $13.5 million mansion.
The 27-year-old star is said to have purchased the property with her fiance Olivier Sarkozy in Turtle Bay, Manhattan after seeking out a home in a more private area.
According to the New York Post newspaper's Page Six column, the couple have settled on a mansion in the neighbourhood.
Along with a private garage, it is also said to have a ballroom, five bedrooms, an elevator and artist's studio.
It is thought to be ideal for the actress-turned-fashion designer, following recent reports she was keen on a more private, secluded home with her fiance.
She was unhappy with the East 10th Street townhouse she and Olivier bought in New York City in 2012 because it didn't feel secure enough, and sold the property despite never moving in.
The couple - who got engaged in February last year - bought the home for $6.25 million and had been searching for their perfect home.
An insider had said: "Mary-Kate was not happy with the house, it was not private enough for her. She needs a garage or something with a more secure entrance."

Aloe Blacc has criticised 'Blurred Lines' - branding the track "immoral".
The 'Wake Me Up' hitmaker has spoken out about Robin Thicke's controversial number one single and says he's glad his collaboration with dance artist Avicii was competing with it in the charts because it provided a "balance" to the "immoral" messages.
He said: "There's really no problem with the song ['Blurred Lines'] aside from the subtle innuendos that are made glaringly apparent in the music video.
"It's an important thing what we do with music. Music is a spiritual experience whether you want to admit it or not, music opens your senses and has been used historically as a conduit to your inner psyche.
"So when we do this as musicians ... to open people up and then to dump trash into them, is to me, no matter what your religion is it's sacrilege, it's immoral."
The 35-year-old star, who has seven-month-old daughter Mandela with his wife Maya Jupiter, thinks the lyrics in 'Blurred Lines' provides a confusing message to young boys and girls about what is and isn't acceptable.
He explained to BANG Showbiz: "The machismo, the misogyny, the violence, the disrespect ... I just don't think it's necessary and I actually think it's damaging to the psyche of young girls and it's damaging to the psyche of young guys who sort of fantasise in this world of being macho and sexist."

Ron Howard would have "chickened out" of directing Jay Z's movie if he had thought more about it.
The acclaimed filmmaker was approached weeks before the rapper's 'Made in America' festival in Philadelphia last year to document the event and only said yes because he didn't have time to properly consider the offer.
He said: "They asked a few weeks before the festival, so I didn't have time to say no. I'd have chickened out if I'd thought about it too much."
Ron believes he was asked to direct the documentary, which is also called 'Made in America', because he was an "extreme" choice when it came to echoing the messages of diversity in the event.
He explained: "The festival represents the breaking down of genres, race and expectation across America. Inviting me in is an extreme version of that."
And working on the film gave the 60-year-old director the chance to gain a broader musical education.
He told NME magazine: "I didn't know Jill Scott or The Hives. Loved them. Rita Ora was a blast. And Odd Future. I won't listen to them every day, but I was impressed with their energy."

Drew Barrymore wants to focus on her family instead of working so much.
The 39-year-old actress - who welcomed second daughter Frankie into the world earlier this week - is ready to make changes to her life that will allow her to spend more time with husband Will Kopelman, their new baby and elder daughter Olive, 19 months.
She explained in an interview conducted before she gave birth: "I want to lead a very different kind of life and enjoy my time with my family.
"It's always been about film or a film production, producing, acting - every little detail that goes into film-making. I didn't know how to have a life under those circumstances.
"When you're on a film, you're in the middle of nowhere working 18 hours a day and it's really hard to have a life.
"I commend people who seem to balance it. I'm not sure how they do it."
Drew first took time out from work and decided to look elsewhere for fulfillment after a project collapsed and made her realise she could be happy with other things..
She told Britain's HELLO! magazine: "That was very frustrating, and I kind of saw that working all the time wasn't the answer for me. I took a trip to India and Bhutan and it was the kind of time you spend alone really thinking about your life.
"I decided I needed to take a break and change things. You're afraid to let go of the life you've gotten used to, but taking that time away from work was probably what led to the place where I was ready to meet my husband and figure out how to be happy with him and also to be a good mom."

Donnie Wahlberg asked Jenny McCarthy's son for her hand in marriage before proposing.
The New Kids on the Block star popped the question to 'The View' presenter earlier this month after her 11-year-old son, Evan, who she has with her ex-husband John Mallory Asher, gave him his seal of approval.
A source said: "Donnie asked Evan if it would OK to ask his mom to marry him."
After Evan said yes, Donnie enlisted him to deliver handwritten notes with the words "will", "you" and "marry" on them to Jenny before he appeared wearing a T-shirt printed with the final part of the message, "me?"
And the insider told Us Weekly magazine: "Jenny is incredibly happy with Donnie and vice versa. He's really supportive of everything she does.
"Donnie is her rock. He's everything Jenny needs but has never experienced in a relationship."
The couple don't plan to get married until next year, however.
The source said: "(It) won't be as big as her first," but it will be "classy and chic."

Vicky Pattison lives in "abject fear" that she'll get fat again.
The 26-year-old reality star unveiled her size 6 body to the world last year after losing three stone and despite only having put on a bit of weight since then, going from 8st to 8st 13lbs, she admits she is concerned about piling on the pounds again.
She told Star magazine: "I live in abject fear every day that I'm going to get fat again! Alcohol is the worst thing for you, but I can't drink a lot now - I've turned into a bit of a lightweight."
Vicky - who rose to fame on MTV's 'Geordie Shore' and is currently starring on new reality series 'Ex On The Beach' - also claims men are attracted her slim figure and new found confidence.
She explained: "I think it's horrible to say, but the majority of blokes obviously prefer slimmer women, but then it could be something to do with my confidence now.
"When I was bigger I would hide myself away in baggy clothes, sit at the back of all my friends and I wouldn't approach anyone. Now, I'm the life and soul of the party again. I'm not sitting at the back, hoping they don't touch a roll of fat!"

Snooki and JWoww are glad they "can be fat together."
The former 'Jersey Shore' co-stars, who are both pregnant, are relieved to have each other's support as they prepare for their new arrivals.
Snooki, who already has 20-month-old son Lorenzo with fiancé Jionni LaValle, told E! News: "It's definitely helped a lot because when I was pregnant for the first time, I didn't have anybody. But now, I feel like we can be fat together, we can complain about the same things. And we're only three months apart from each other, so we kind of get each other now."
JWoww added: "And I just ask her a million questions. And no matter how graphic, disgusting and uncomfortable they are, she has the most phenomenal answers."
JWoww, real name Jenni Farley, will welcome a baby girl in July with fiancé Roger Matthews, while Snooki, real name Nicole Polozzi, will give birth to her second child in September.
Asked what's the best piece of advice she has received from her best pal, JWoww, 28, said: "That everything's normal. When I'm like, 'This is literally so strange and weird and crazy,' she's like, 'No, it's normal. It's fine.' "