At work I will sometimes go out to eat with my co-workers, and we usually split the bill & tip.
Most of the time I am
appalled at how little some people will chip in. They either assume the rest of us will cover their share of the tip, or they are just plain cheap.
It's pretty embarassing and irritating to me when a group of us leaves a really small tip, especially when I know I've already put down more than my fair share and others have not. (And I'm not going to put in even
more money just to cover for their cheapness.)
When I see it happening I'm not quiet about it. I do speak up, and I don't mince my words on this issue. The last time it happened I managed to shame my co-workers into leaving a decent tip.
The reason I'm sensitive to this is that my SIL was a waitress for a short time, and she told me horror stories about bad tips, and even non-existant tips from overly demanding, fussy, rude, cheapskates. She hustled
hard and cheerfully for these people, and was often rewarded with lousy tips. Sometimes she didn't get one at all!
Needless to say, her stories have inspired me to be a better tipper (although I will only tip the bare minimum for bad service, and I may leave even less than that if the service was truly terrible).