Britney Stumbles -- Almost Drops Baby Sean

Oops, she almost did it again. Britney Spears stumbled this afternoon as she was leaving a New York City hotel and almost dropped little Sean Preston.

We're told Britney was leaving the Ritz Carlton, holding a drink in her right hand and Sean in her left as she maneuvered through a crowd of onlookers. Britney moves through the crowd and then she suddenly trips, the baby's head goes backward and his hat flies off his head. Britney regained her balance and the baby seemed ok.

Update 7:15PM ET: After the incident, Spears said, "This is why I need a gun."

TMZ will post exclusive video of the incident Friday night at 7:00PM ET.

It's the latest in a series of mishaps. A few days ago, the singer was driving in her convertible Mini Cooper with Sean in the back, facing forward -- not a good idea says the State of California.