El................. in the room

once upon a time, there was a 25 cousins. They had a VERY large living room. Every time they go sit there watch TV or talk about something serious "e.g, discussing the latest cartoon movie they saw", there was something gray moving around. The weird thing is that they never talk about it, only the youngest cousin always say "heeeey can't you see this big gray moving thing", they just look to each other and say nothing.
days passed and some of the 25 cousins died and their children came instead of the passed away older fathers, the most important is that they still 25 cousins :).
one day they were sitting in their living room talking and suddenly the youngest cousin said HELPPPPPPP HELPPPPPPPPPPP the big gray thing hit me, i'm bleeeeeeedinggggg :(.
At this point the Older cousin said, there is nothing called big gray thing you hit yourself into the wall and you are making this big gray thing story. Another cousin said, noooo it was the gray cat, you pulled her tail so she hurt you. They went for discussion for over than 20 days and the youngest cousin was still bleeding.....
after a lots of discussions a guest came to visit them, and they used to be very welcoming with the guests. once the guest entered the living room he said "What is that Elephant doing in your living room??!!!".
And they still don't see the Elephant, oh sorry the big gray thing.