I'm confused. Did you think the emergency exit aisle seat would be empty? That's delusional. We're you constantly checking the seating chart to see if that seat was reserved? Paranoid.
You might have a point if you booked aisle window near the back of the plane. No "normal" person would select that seat if numerous better seats where available.
Selecting the aisle seat, next to the couple is the polite thing to do. Leaving the 2 seats for a couple makes sense. The single aisle seat may have been the suggested seat.
