- if you don't offer someone tea when they come to visit, you are rude. if they refuse, and you accept their first offer without insisting, that's also rude. you have to persist a bit. this was parodied in the TV show "Father Ted" but it has some truth to it
- additionally, if someone says yes to a cup and you don't offer a second cup a while later, probably rude
- if you don't have biscuits, you need to apologise and explain why.
- if you drink green tea or anything other than black "breakfast" tea, you're "fancy"
- Households are either "Barrys Tea" or "Lyons Tea" and people are expected to have a loyal devotion to one and hatred of the other. Other brands (non-irish) are ridiculed, although we all drink all kinds. (Note - this rivalry also extends to 'crisps' or potato snacks - you're either Tayto or Kings)
- some people prefer coffee which is fine, but if you don't like either you're considered odd