Well, in our religion (islam). We not that mad if orther people who not same religion do something like that. We still respect them and reject the food in good/kind manners. We have a manners rule too you know, of course it's included the visiting manners, we respect the host.
Damn, reading this manga as same as reading school book. It's like teaching u to change form gloomy or orther to "Normal". It's very helpful though. This is a good manga.