It was meant to be the happiest period of their relationship - fresh from winning the UK's hottest talent show Stacey Dooley and boyfriend Sam Tucknott were looking forward to a fantastic Christmas.
But, as personal trainer Sam later described, it was as though Stacey had already left their relationship.
She later admitted to a new romance with her professional dance partner Kevin Clifton after hunky Sam saw a "I love you" text on her phone.
Sam later described the last weeks of their relationship as "hollow" and is now berating himself for not realising Stacey, 30, was falling for divorced Kevin.
Speaking to the Mail On Sunday, he describes himself as "naive" to not notice his relationship was changing.
The 30-year-old said when Stacey was first accepted for Strictly the couple were thrilled. At first Sam and Kevin were close and exhanged banter over Intstagram but as the competition went on, Sam said the Strictly professional started acting "sulky" and even stopped replying to his messages.
Stacey Dooley DATING Strictly's Kevin Clifton as her ex finds 'secret texts'
Stacey and Kevin would often train harder than any of the other dancers, Sam said, so he looked forward to getting "my Stace" back when the show was over.
Instead their relationship was about to shatter. Stacey shunned low key dates with Sam - including a December 23 Christmas party.
She chose to go to Brighton’s Theatre Royal with Kevin to watch his sister Joanne star in The Rocky Horror Show.
Sam later described a "hollow" Christmas Day at his parents which ended with a "tense" Boxing Day.
Sam says: "I love Christmas and I just felt she was not at the table. Someone said, 'What’s the matter with you two?', and it sparked me to say, 'I don’t know what’s up with her.' I know we’re not falling into each other’s arms but I don’t know why. Why are we not having a nice Christmas?
"I could just sense that something was up and I didn’t know what it was. I thought maybe she was tired, but she had just won Strictly – she should have been buzzing."
Lifting the lid on Stacey and Kevin's undercover romance, Sam claims to have rumbled what was going on between the pair when he found incriminating text messages on his girlfriend's phone.
Personal trainer Sam, 30, fired: “The blame is with Kevin. He’s an absolute rat.
"I was getting my stuff to leave. Stacey was in the loo.
“Her phone went and it was Kevin Clifton — ‘I love you’ with a red love heart," Sam told The Sun.
He then claims that later that day - after he'd moved out of their shared Brighton flat - Stacey messaged to confess that she'd fallen for Kevin.
But the documentary maker insisted things hadn't started up with the dance pro until her relationship with Sam was over.
A devastated Sam said he replied back to say he 'hated' what his girlfriend of five years had done to him.
While Stacey came clean days after their relationship ending, Sam claims to have noticed several 'red flags' about her friendship with Kevin as she competed on the BBC dance show.
Sam claims Kevin would send Stacey gushing text messages but remained 'sulky'' and 'distant' around him.
When news of Sam and Stacey's split was announced in March, the break up had been put down to conflicting schedules, though there continuing growing rumours Stacey had fallen for her former Strictly mentor.
Viewers of the BBC dance series had noted documentary-maker Stacey and ballroom champ Kevin's undeniable chemistry - with their successful partnership ending in them lifting the glitterball trophy together in December.
It had been alleged during Stacey's time in the competition that her boyfriend Sam was becoming increasingly jealous of her close relationship with Kevin, who split from his wife Karen Clifton months before.
Stacey, 31, hit out at the speculation in an interview with The Times, insisting that her partnership with Grimsby-born Kevin, 36, was purely platonic.
"The truth is Kevin and I are brilliant friends and he’ll be my pal for life,” she told The Times Magazine in Feburary.
“And Sam was probably the most supportive he has ever been. When I first got the gig he was just so made up.
"He was dancing around our living room. And every week he’d say, ‘Listen to Kevin. Kevin knows best," Stacey added. “He was a dream.”
Since the first series in 2004, Strictly has become as much known for its multitude of relationship scandals as its dance routines.
Among the couples that didn't survive the show include Louise and Jamie Redknapp, Georgia May Foote and Giovanni Pernice and Countdown's Rachel Riley and her husband.
However, there have been some success stories over the years.
Gemma Atkinson and Gorka Marquez announced this year they are expecting a baby together after meeting on the show.
While former dancer Kristina Rihanoff shares a baby with ex rugby star Ben Cohen after they were introduced on the dancefloor.
