First used by Gareth Lewis to describe a night where police where called to eject men in their late twenties from an 18 year old girls birthday party....Bad Scenes!
The word has evolved to many things.
1) Describing events of an unpleasant nature.
2) Debauched goings on.
3) Unpleasant, yet entertaining acts of lunacy.
4) Antics instigated by drugs or alcohol.
5) Ugly bird/bloke.