The only time I mention tips is when I take the little one's out. I know and the staff know they are going to be messy. Usually a joke about how big a mess they make determines their tip and laughs and special attention to the kids result. The best way to get a bigger tip with me is to give my lil "darlins" VIP treatment:') Only a few times have I left without a tip and I followed up with a call to the manager. Yall are talking about higher scale "diners" though. I try to tip all food related service people. Sometimes I have to complain to the manager because they aren't allowed to accept though. I would have expected Kerry to have left a dollar or two on that Wendy's table.
Why should he have? One doesn't tip at fast-food restaurants. At least, not here in Houston.