Haha, what was that lecture? The male MC is an elementary school teacher, I assume, based on this.
I'm pretty sure the punk woman wasn't there to make friends in the first place. Although she's a fool for suddenly starting to badmouth an unknown person's sense of fashion in the middle of the street, her reaction after the dude's lecture was on point.
He diffused it in the best possible way, defending his gf, non aggressive, not provoking the other side, while making the other side conscious of their behavior.