Weird, must be a regional/cultural thing, because where I live no way anybody would expect that just because you invited them over you'd pay for everything =/ unless maybe it's somebody from another country, but even that would depend on the situation.

I mean, hosting at home is one thing. You're to somebody's house, it's accepted that they feed you. But if I went to my friend's and she suggested going to a museum, I wouldn't for an instant assume she meant to pay my ticket.