A phraseused to describe those moments you can't say what you are really thinking but want to let something out - usuallyused when in company so language is restrained. Works well in a variety of pronounications e.g.
long and stretched - bug - ger - rug - ger,
short and angry - buggerrugger
mumbled and infuriated - best used when someone is annoying you.
First invented in 1992 (ish).
Oh Bugger Rugger - I've knocked the full glass of wine over.