mine occured just this last summer.
there were 2 very pretty ladies downstream kicking back on a rock when one stood up and pinched a loaf in front of the other one
only instead of dropping into the stream it plopped on the side of the flat rock and just sat there while the 2 babes stood there dumbfounded as to what to do next to knock the "bung-goo" off the rock.
eventually the other babe got up and said in a valley girl voice
" that was grrrr-ossss"..
and stormed off while the other sat there in embarressment