Jason Trawick reportedly used the pop star's father Jamie to break up with her, leaving her out of everything, reported Radar online.
"Jason wanted out, and in the fragile state that Britney is in, it's not like he could have a rational conversation with her about it, so it was really between him and Jamie," a source said.
"Jason and Jamie wanted to make sure that Britney didn't lose it, so they had to water things down for her a bit. But she knows that the engagement is off and that Jason has been removed from the conservator ship," it added.
Jamie had been co-conservator of Britney's affairs with Jason.
The troubled pop star, 31, severed ties with The X Factor USA last week after serving as a judge on the series for one season.
In 2007 she suffered a public meltdown, shaving off her hair, after her split with then-husband Kevin Federline.
