I live in Boston, which is about as young-and-transplanty as it gets.

I don't know, maybe I just hang out with folks who take friendship with a degree of seriousness, but nobody I know would need to dun somebody in either our group or our extended group to pay their share. You grab the bill, you eyeball it for your stuff, you add twenty percent for tip, you're done.

If you try to freeload, you just wouldn't be invited again. Because friends don't do that, just as they don't send each other invoices.