Sorry, but the handicapped restrooms on the Boeing 777's that I have been on have been big enough for people to try the Mile High club with witnesses.

Not that this has not been done on recent trans-Atlantic flights, but this would be a bit more private.

I am not one to agree with this thread. Although, I do have an (rented) apartment where the master bath is both larger than the kitchen and has more drawers than the kitchen.