Celebrity agent Trawick plans to call it quits after "The X Factor US's", on which Spears is a judge, current season is finished, reported Aceshowbiz.
The duo have have been engaged for over two years.
"Jason has told Britney's entire family that he's planning to leave her, so that Britney will have a support system when he breaks the bad news. He wants to call it quits, but not their professional relationship," a source said.
Before the breakup rumor emerged, Spears took to Twitter to wish her agent fiance a very happy birthday.
"There are def going to be a few more candles on your cake tonight @JasonTrawick. Happy birthday baby Love you so much!" she wrote.
