My ENTj friend and i have the strangest sense of humour. What ive noticed is we have a very similar minds eye when imagining odd situations. I can tell he is imagining the scenario exactly the same as me. I will try to give examples as im not good at explaining.
Like tonight we were eating yiros really fast as we were in a hurry. We were looking for somewhere to eat and it happened to be near a circus in town. I said that eating the way we are they will probablly direct us out onto the circus stage and perform a yiros eating dance, or portray us as cannibals due to all the meat on our faces.
Or at bowling we started talking about prizes, and one of us came up with a naked women slowly getting lowered from the ceiling and getting all twisted up as she lowered.
Or he pretends like if he was black or rich or good at getting women he would kind of pick them up like rag dolls and slam them then throw them away in quick succession. Of course joking.
Tonight we went to see 'There Will Be Blood. I was like this is nothing like the oil in Saudi Arabia. Hes like yeah you turn on the shower and oil comes out. I was like yeah it rains oil there. Then we just went all silly. Daniel day lewis went into a bar and my friend put on a daniel-day lewis voice and said "one shot of pure oil please". Then the ESTj said that looks like Australia, Ayers rock. And now i put on a daniel-day lewis voice and said "I didn't know there was oil in Ularu, is that what made the aboriginals black?". Then yea oil jokes kept going about how he dipped his black spotted dog in oil etc.
So i really cant explain why these type of things are funny to us. I knew in describing them they wouldn't be. I thought perhaps its Ni as its his 2nd strongest and my 3rd strongest function?