Slightly off topic but as an Ulsterwoman who went to live in England... the rules about 'would you like' are different! Caught me out completely.
I'll ask if you would like a cup of coffee or tea if you enter my house... well just about for any reason other than because you're trying to sell me something. Now the way I was brought up? You say no, no, you couldn't trouble me, and that's you being polite. So I assure you that it's no trouble and then you may say yes or no as you please.
The English, as far as I can tell, take that first refusal as final. I can't tell you how many times I ended up with my tongue knotted with thirst because my upbringing wouldn't allow me to say yes the first time, and the second time never came!
Also, if you arrive at my house at or around a mealtime, I must invite you to stay. That's good etiquette where I come from. Equally, you must say no. This time it works slightly differently. If I don't ask again, then that means that it was purely a politeness thing, or we're having something that won't stretch to one more. But if I ask you a second time, then it's a casserole which will go round one more without too much trouble, and it's perfectly polite of you to say either yes or no as you please.
Let's not get started on the older-fashioned of us, for whom the inability to offer you a home made biscuit or scone or cake brought on soul-searing shame... or the fact that offering a shop-bought cake is a carefully honed insult, only to be wiped out in blood...