I have a friend that i'll quite often invite over for a drink. We've been friends since 6th form, and we've never really grown out of 'fancy coming over for a drink' at the drop of the hat, and we drink a fair amount in an evening! It's literally been years but it clicked the other day that he never brings a bottle or anything with him unless I ask. Now he's quite often my 'plus one' to friends parties to those who have known us since being 17 but he never takes a bottle with him.
Say I was having friends over I would get enough drink for everyone. But as he comes over regularly just for the purpose to have a fair amount to drink (both grown out of clubbing but no local pubs any more) who is being unreasonable?