We've all been there—it's a big friend group dinner. It took weeks to plan and some of these friends you hardly ever see, so you really really want to go. But then the anxiety starts to set in when you start about how that splitting of the check is going to go down. Some friends are in the mindset of “just split everything down the middle!” Even though some people ordered $20 cocktails and prime rib and you just got water and a side salad. Others are all about separate checks, but who will be t…