three seats to the wind

My flight last night from New York to London wasn't crowded, so I had 3 seats to myself & I could actually lie down & sleep for a while. Across the aisle from me was a young woman wearing purple sneakers who seemed to be doing a good job of sleeping in only 2 seats, all curled up, but sometime in the night I got up to go to the bathroom & when I came back she was lying all spread out in my 3 seats. But when she saw me looking confusedly at the row numbers she got up and sheepishly slunk back to her own place.