We've hosted some friends and family gatherings over Christmas and on a couple of occasions guests kindly offered to bring food (home baked cake, biscuits etc).
I was a bit shocked when, on leaving, they packaged up leftovers (of their contribution) and took it home (uninvited). When I take food / drink to a party I consider it a gift / contribution and would dream of reclaiming it at the end of the evening. AIBU?