The fallen pop star forked out to have her lips plumped up last week but ended up with slightly more than she bargained for.
Britney had hoped to keep the beauty treatment a secret, making a hush-hush visit to a plastic surgeon in Beverly Hills last week – and came out concealing her mouth.
Looking swell: Britney and her full lips after visiting a cosmetic surgery clinic
Yet the following day she revealed her new pout to the world when she was snapped in oversized shades.
A LA source said: "Brit hoped her new lips would improve her look without being really obvious to anyone.
"But onlookers literally stood opened mouthed when they saw her. She looked freaky."
Britney keeps a stiff upper lip about her recent beauty treatment.
The new look comes a few days after Miss Spears's lawyers reached an out-of-court settlement in her hit and run case.
The singer, 25, was ordered to pay around £500 after hitting a parked car when driving without a valid California licence.
But the payout did not seem to concern Miss Spears.
Oops! Britney Spears got more than she bargained for when she forked out to plump her lips up
At one point on Friday she was photographed dancing around her LA home in a bikini – perhaps in excitement about Saturday's day out with her sons.
Unfortunately, their quality bonding time was slightly hampered by the presence of the monitor she has been allocated during her acrimonious, and ongoing, child custody dispute with estranged husband Kevin Federline.
Like Leslie Ash Britney's attempt to have fuller luscious lips has resulted in a trout pout
The singer has regained visitation rights of her sons, Preston, 2, and Jayden James, 1.
The singer on Saturday was spotted driving with her children in Studio City, Calif, in her white Mercedes convertible, which was decorated with pumpkins on the dashboard.
Hippy shake: She dances at home
A presumed court-appointed monitor was seated in the front seat, with her sons in the rear.
On Wednesday, L.A. Superior Court Commissioner Scott Gordon had temporarily suspended her visitation rights.
A source close to Spears said the judge removed her rights after the pop star was unreachable by a cell phone designated for court-related scheduling.
On Thursday, Kevin Federline's lawyer, Mark Vincent Kaplan, said he expected Spears would get visitation reinstated soon because "she has complied with the part of the order [causing the suspension]."
Lawyers for both sides did not respond to calls for comment.
