Many years back in my younger days I was in a Walking Street disco, I see a nice looking Thai lady standing alone, so I go up to her and say something harmless like "Hello, how are you?" and she politely smiles, then some farang that was just off to the side talking to someone else at the next table gets in my face with his chest puffed out, arms popped out to the side like he's ready to throw a punch, angrily saying that's his gf. I quickly say ok, I didn't know and stepped away. Some farangs are too quick to want to fight over their gfs/wives.
We don't know if the Russian was aware of the lady's status or was or was not warned to step back, had to say it's his fault without more info.