Walking around Sydney suburbs in an "I love Melbourne" T-shirt?

People in Sydney wouldn't care. They've scarcely noticed there is a city down there.

To really rub it in, wear it to a Sydney Swans vs any Melbourne side game in Sydney (and make sure your seating is in the Swans section).

Footnote:

A mate of mine once did something similar. At a Sydney Swans vs West Coast Eagles game, he sat in the middle of the Swans fans in blue and gold Eagles supporter garb just to bait them. Amazingly he got out alive.

would be more dangerous wearing a sydney shirt in melbourne

Those of us who live in Sydney would just ignore you. Because we are the best we don't have to declare it. You only have to get arrogant about it if you realise that you aren't as good. LOL

Nobody really cares what words u have on ya t shirt around here, I mean nobody really notices

Meh. I'll immediately forget it the moment I walk past.

you might get kicked in the nuts. Up to you good luck

Somehow I don't think that would be a good idea lol

Not unless you've got a death wish !