Here's a potential solution. Find the waitress. Give her a generous tip, if you can. Then go meet your friend and say,Something has been bothering me and I want to talk to you about it.Tell him what you know about the low tip and what you think about it. Make sure he didn't leave something else that your wife didn't see. He could have put 5% on the bill for her taxes and left her a 20 under the check for all you know (or a nice track which is priceless in value ). Anyway, if he left a 5% tip, then you tell him you went back and tipped the waitress later. That will probably make him feel uncomfortable, probably, and the incident might stick out in his mind. He might think about it, and hopefully he'll learn his lesson. We can pray for him to