Here's Brandi Glanville's idea of charity -- proudly exposing her nipples at a fundraiser. She's a giver!

Brandi and Susan McKagan, Duff's wife, attended Rhonda's Kiss charity concert for cancer patients Tuesday night at the El Rey Theater -- where, apparently, the dress code was top optional.

Outside, an absolutely parched Brandi tried to apply logic to her decision to openly sport heart-shaped pasties. Fashion is a very subjective thing. Obviously.