Splitting the check

[Gambitgirl]

if they say it's easier to stick you with $15-20 you didn't consume than it is to figure out the check, then it's time for you to pull a mini-calculator out of your bag and offer to figure out the bill for them. if you have already pointed out that it is unfair for you to pay for drinks you didn't have (so other pay less for ones they did) and they ignored your objection, then you have every right to flat out say you are not paying that extra $20. they can all divinde the $20 by the number of drinkers and they cover it. even a 4th grader know how to divide.

they're being rude to you.

[Sirius]

Mr. Sirius and I flatly refuse to pay for other peoples' alcohol.  Most of the people I've gone to dinner and split checks with have always paid for their own alcohol.  As for splitting checks, Mr. Sirius is a math whiz who can figure checks in his head, including sales tax and tip, in less time than it takes to fish out a calculator.   

[Malla]

If it's a restaurant you frequent, you could discreetly inquire if they can create a "bar bill" and "meal bill" if separate checks won't work for your group--many places I go to have that opition.  That way you can put in for the meal bill but not the bar bill.