When you 'bum' something or someone this means you tend to become obsessed with the thing you bum. It means when you like something/someone a little too much.
Australians that vape, go out, drink, party, wannabe gangstas. Bums can be defined as brown people who go to garden city in South-East Queensland (Australia). Another definition for bums can be brown, islanders that do drugs or just vape and drink.