I wonder what they argued over…

I was on my way home after a night out in Camden Town (a rare event as I’ve spent a few years disliking the place) and shared a Tube carriage with this couple, but everything in their body language told me they were strangers. They were obeying the laws of personal space.
Medium: Digital drawing on iPhone 6+ and Adobe Ideas app
Date drawn: 29th November – 23rd December 2014