stay out of your brother's airspace

This is how it goes in my house....The three of them are constantly testing each other. Recently my 11 yr old got his own room. This meant my 7 yr old son and his 4 yr old sister are sharing a room. I can hear you grumbling now but so far it works for us. Anyway, to push his brothers buttons, G will stand outside E's door and pretend like he's going to "cross the magical border". In a response to Please stay out of your brother's room he says I'm an airplane. Hence, the stay out of your brothers airspace. This was met with laughter and the two youngest running around the house pretending to be airplanes and testing the new no fly zone. E is still trying (?) to perfect the "ignore them and they will go away" technique that I perfected so many years ago. This one comes in handy at 8pm when they are all yelling because they are hungry. why could they be hungry at 8pm? Because at 6pm their dinner went uneaten back into the bowl, pot or sink, depending on what it was and who will finish it later (dad).