Steps to Duplicate a friends items
step 1: Punch him in face until he goes unconcious
step 2: Go to hes inventory without taking anything yet(just been able watch at hes items)
step 3:wait for him to get up and exit the game(at this point you will see the animation of exiting or also he can tell you he is exiting
step 4:you have around 30 seconds to drag hes items on your player (until you cant see him anymore )
step 5: he is logging back in and tada you both have the same items(he still have hes items as so do you )