Britney Spears and Jason Trawick
01/15/2013 at 07:00 AM EST
once believed in a fairy-tale ending for herself and Jason Trawick. But by mid-December, she was no longer wearing her engagement ring, and she knew it just wasn't going to happen,
a source close to her family tells PEOPLE.
"Britney spent Christmas in L.A. with [sons] Preston and Jayden. Jason was around for parts of the holiday, but it was very obvious that they were not really together anymore," the source says.
"They were not affectionate and instead just seemed to keep things going for the boys' sake. Britney looked a bit gloomy and tense over the holidays."
Trawick, 41, moved out after the holidays, and the couple officially announced their split
Having dated her former agent since 2009,
and been engaged for a year,
Spears, 31, had been talking a lot about her wedding last summer. "But lately she acted like she knew it would not happen," the source says. "She hasn't talked about her wedding plans in a couple of months."
That was quite a change from the early months of her engagement, when Spears was very focused on wedding planning. "She would spend hours online looking at dresses and dreaming," says the source.
Another source says the pair's problems were significant enough that they had never set a wedding date.
"Britney wanted to rush in, but there were things that needed to improve before they got to that place," this source says.
"They love each other, but like any relationship, and especially this one, there were some major challenges and hurdles and constant work that needed to be done. At the end of the day, it just wasn't working, and things were't going to change, so it was time to let go."
Reporting by PERNILLA CEDENHEIM and JENNIFER GARCIA