DON’T RAIN ON HER PARADE DEPT.: Dyed-in-the-wool Demo-crone BARBRA STREISAND, prepping for her at-home-in-Malibu fundraiser honoring Speaker of the House NANCY PELOSI, drove to her fave BevHills florist – but floored it and fled when she spotted…EEeek!… customers inside.

Phoning the store, La Streisand warned she was on her way in and demanded: (1) get all customers OUT immediately so there’s no gawking;

(2) NO SMOKING…even outside in the back alley where workers construct flower arrangements; and…

(3) drape a tarp over the front window so passersby can’t stare — or snap snapshots!

When the haughty thrush returned moments later, customers were being bum-rushed out, all back-alley boys had snuffed their butts, the window was draped as demanded — and a florist flunky was waiting to park the Diva-mobile!