I think what some of you all don't seem to understand is that we will and have on several occasions picked up the tab for someone, but it is a planned thing. Birthday dinners come to mind, or if just us an another couple, sure we will buy the wine even if the other couples drink it. We have been known to buy a couple of bottles and pay for them, ( good work bonus) And that was a way of celebrating with friends. But I would never want to assume or have any of my friends think that I assumed that they would ever feel they had to cover part of my meal because of trying to split a check evenly.
We LOVE going out with friends, and luckily our friends work the same way we do. I guess when you don't know the details of peoples lives, it is hard to get across. Like my friend who took me out tonight, and she paid, but she told me she was. We had her DD with my DH and my DD, he tool the girls out to dinner and paid. We do this on a routine basis. But when dinner's are a planned affair, with or without kids, we do go to fairly upscale to upscale restaurants and we are always asked by the server, when ordering, how we want to split up the checks. Usually they don't even ask if we want them split, they just assume. If someone is paying for more, they just say put it on mine. No cheapness, no hard feelings. We take care of each other on a day to day basis.
If you do it differently in your area then fine, but those of us that don't aren't cheap.