Rude Much?

My first trip to New York, entering the subway, someone walked in front of another person causing them to break their stride for a fraction of a second. Which led to the following exchange without pause or hesitation from either party, shouted at each other as they walked in opposite directions:
“You’re an a-hole!”
“Your mother’s an a-hole!”
“You don’t even know who your mother is!”
“She knows you’re an a-hole!”
Fade.