Britney’s Addiction? Spears 'Obsessed' With Exercising To Please Her Boyfriend

Britney Spears is obsessed with staying in perfect shape, and a source has told RadarOnline.com she's doing it to keep her much younger boy toy, Sam Asghari!

The pop star, 36, "looks amazing and she’s got her best body ever, but she’s letting her obsession with diet and fitness rule her life to an unhealthy degree," an insider revealed.

"She’s so self-conscious and can’t go five seconds without talking about cleanses or weight training."

Friends say Spears is desperate to stay slim and hold onto her hotness to please her much Asghari, just 23, whom she met a year ago on the set of her video for “Slumber Party.”

"Even though she looks incredible, she still Photoshops her selfies all the time," the source said.

"It’s as if she’s on a weird mission to constantly look picture perfect. She’s always scrutinizing her reflection in the mirror and sometimes takes 50 photos before she’ll post one to Instagram."

Asgahri, who repeatedly claims to be head-over-heels for the pop singer, also loves hikes and working out, and friends worry Spears is so busy making sure he sticks around, she’s ignoring her own life.

As RadarOnline.com has recently reported, Spears is demanding everyone around her adopt a healthy lifestyle, including no more partying and no more alcohol on tour.

"People are happy that Britney is taking care of herself, but now it’s getting in the way of her having fun," the insider said.