Dedicated to @YTShadowWolf and @X_Huke_Lemmings_X thank you guys for commenting!!

Tony -

He takes one of your hoodies that smells like you so that he can feel like he's always with you, even when he's not

Steve -

Your laptop because he keeps misplacing his own and he wants to keep up to date on the world's events

Clint -

He borrows your phone so that he can try (and fail) to prank call some of the other Avengers

Bruce - 

Your car. He had lost the keys for his own car and was in a rush to get to work so he took yours. Without asking!

Thor - 

He borrowed your favourite teddy bear as he was curious why you were so attached to it and what your response would be like if it went missing

Loki -

Loki borrowed your lucky crystal in the hope that it would bring him luck as well