A friend recently voiced this dilemma: "What to do when your dinner companion tips too little and there's no chance to discreetly slip the waiter some extra $$? I feel terrible!"
I tweeted out to the @seriouseats followers for advice and got a number of responses that might have helped our friend in need. Many involved using an excuse to go back so you can supplement the tip. (I've done this before; "visiting the restroom" is an unassailable excuse to go back in.)
@MissExpatria suggests saying, "Sorry, it's a thing with me, I have to leave X percent or I won't sleep tonight, it's not you, it's me."
That's honest and straightforward enough, but I wonder how some folks might take it. It could be seen as a rebuke—not to mention the fact that tipping practices differ from person to person, and the custom often evokes heated discussion.
What would you do?