When I finish a meal in a restaurant, which expression to pay for the food is more idiomatic?
If they're both not idiomatic enough, please list the alternatives.
Also, if I want everyone to pay separately, what would be the idiomatic ways to ask for this?
"Check out" is actually a separate idiom that is not applicable in this context; it refers to the procedure of a formal action of leaving some place where you had been booked in, like a hotel. In "check out", the word "check" is actually a verb -- not a noun. "Check, please" sounds perfectly fine, I cannot possibly see how it could be interpreted as "blunt" or "impolite". Seeing it as insulting surprises me as being grotesquely over-sensitized, and gives me the impression that the dictionary definition word "insult" has been, unbeknownst to be, replaced overnight with something completely different from the original meaning. Being curt with one's words does not equal being impolite, especially since this phrase uses the word "please". Being polite also means respecting the other person's time and not wasting it by making them participate in unnecessary exchange of verbose platitudes and pleasantries. And also, you might want to use an appropriate regionalism; "check" for American and Canadian English, "bill" for British and Australian English.
The most common phrasing is “check, please.” I think this sounds a little blunt so I often say “Could I get the check please?” which I think is a little more polite.
If you want to pay separately, just ask the server for “separate checks” at the beginning of the meal.
