The 'Toxic' singer was visibly annoyed after her oldest child Sean Preston, 11, jumped out at her after lying in wait quietly.
In a video posted to the singer's Instagram page, which appeared to have been filmed by her youngest son, 10-year-old Jaden, Preston said: "We're about to scare the heck out of mom. We stole her phone, and she's gonna walk through...She's walking."
Britney then walked through the room and screamed and fell to the ground as he yelled out to her.
The clearly-annoyed star yelled "Sean Preston" while the youngster laughed.
Britney captioned the video post: "My damn kids".
The 'Piece of Me' hitmaker - who has both boys with her ex-husband Kevin Federline - recently admitted her oldest son thinks he is "much more clever" than she is and won't let her help him with his homework. She said: "I sit and do drawings with Jayden - he's really good at it and I'm horrible.
"I do his homework with him, too, which I love.
"Jayden lets me help him, which Sean Preston never will. He's such a smarty-pants and thinks he's so much more clever than me. I let him think that, but he is actually pretty cool."
And the 34-year-old singer has had her musical horizons broadened by her oldest son too.
She said: "We talk a lot about music.
He's introduced me to some great people like Calvin Harris and Skrillex. If you listen, kids can teach you so much."
Britney's sons have seen her perform at her Las Vegas residency, and though they think the show is "amazing", she insists they're not particularly impressed by her pop career.
She said: "Of course my kids have seen the show. They think it's amazing.
"They completely understand the person I am on stage is an act and it's not Mom.
"When I'm home it's like, 'Hey, can we go to the park?' I don't think they think I'm in any way special. They just think that's my job."