As was mentioned, Sometimes WE pay, sometimes THEY pay...so no one is taking advantage of the other. "Sucking it up" means you pay ALL the time and the other party just joins and not contributing to anything. I believe a real friend does not treat everything friends do together as a business transaction.
This is exactly the way we handled the checks with our friends before, and none of us ever worried about small differences such as a slightly more expensive dish or one extra appetizer. However, I do have a problem with splitting a check evenly when one couple always orders alcohol and the other couple never does. If we continued to split checks evenly despite this disparity, we would be in a position of subsidizing the other couple’s meals to the tune of hundreds of dollars per year.
For some of you, that isn’t a big deal or your consider it a price of the friendship. For me, it doesn’t feel good and I would never suggest other couples split checks evenly with us if the tables were turned.