Hahaha - this cracks me up!
It's amazing how Americans have become so entitled and clueless over the past few decades. I honestly have a hard time even understanding how any parent could think this was acceptable behavior - not only are they blocking the aisle, but what happens if there's sudden turbulence or something? They tell you to sit in your seat with the seatbelt fastened for a reason, you know.
Mindboggling... what was the mothers' reaction when the FA told them to get up and move? Did they apologize, or did they get huffy and indignant?