Co op Key Items

[Adventure Guy]

First off I want to say I love this game. Although I would like to know how to get me and my friend to have boss related items, and quest items. We both own the game but only the host can do certain things which has made him a bit sour to the experience as we will both grind for completing the NPC quest only to have one of us receive the benefits. If there is any way to fix this please let me know!