Means taking risks, pushing your luck, or doing stuff with a whiff of danger, whether it is actually serious or just hilariously petty. Often said with sarcasm when someone does something mildly rebellious and wants credit for it. Honestly, it is the go to phrase for roasting your mate’s tiny “daredevil” moments.
"Mate, you really paid the extra 40p at the corner shop instead of walking to Aldi? Living on the edge. Next you’ll be microwaving tin foil and calling it extreme sports"