<<I booked aisle and window and am holding my breath that the middle seat remains vacant.>>

We were a few rows away from a couple that did that on a flight from CDG to Boston. Just when they thought everyone had boarded, an enormous gent indicated that the center seat was his. He waved off any offer for the aisle or window seat. When the husband stepped aside for the gent to get to his seat, in a flash, he raised the armrests and took his seat. I don't think I've ever seen a couple more miserable on a flight.