Gramma and gramps should have gone to Y to visit children and grandchildren - not the other way around.
I would have gotten up after the second time and gone to the galley to let the FA know of my displeasure with this situation.
I would not really want to confront the offenders, but since all my friends have told me I have lost my filter, I'm sure something interesting would have come out of my mouth.
I pay to have a bit more peace and quiet and unobstructed aisles when going to the lav.
Totally unacceptable.
What kind of aircraft? That should tell you the crew that was working the flight.