Britney Spears recently stunned clubgoers a ‘Blackout’ album release party by stripping with a Winston’s barmaid and feeling her up on Tuesday night.

Britney had knocked back several vodkas and was headed for the ladies room when the bartender caught her eye: “You have nice tits! Mine are all saggy,” the singer told the brunette.

She allegedly demanded they swap clothing– including bras.

“I’m wearing Britney’s bra!”

“The bartender felt that she had no choice but to comply,” a witness tells OK!

Brit later jumped atop a table to dirty-dance to her single Gimme More.