SANDRA BULLOCK ON BRADLEY COOPER

Sandra Bullock hush-hush secrets!

Sandy and her costars Bradley Cooper and Thomas Haden Church were out in force at world famous Mann's Chinese Theatre for preem of new flick All About Steve.  And RadarOnline.com worked the red carpet to get some slammin' sound bites!

Seemingly svelte Sandy dished her top secret diet tip: "Lipo AND  lots of it!"

But Bradley Cooper raised eyebrows as he arrived sans newest gal pal Renee Zellweger.

To feel the heat and get more dirt from Bullock about WHY BRADLEY COOPER as opposed to WHY NOT? CLICK HERE for video and MORE!