It's rude to touch your friend's possessions without their permission.
Matt sees that his friend Ted got a brand new iPhone just like the one he has been wanting to buy.
Matt wants to see what the new phone is like.
Matt asks Ted if he can check out his new iPhone.
Matt takes Ted's phone without asking his permission and begins playing with it.
Ted agrees to let Matt play with his new phone.
Matt gets yelled at by Ted for using his private possessions without asking first.