We're talking about people who you thought were friends, years of time together, etc. RSVP confirmed, you will be paying for their entire meal - hors d'oeuvres meal, dessert, open bar, etc. But then they just No Show. No excuse, just nothing. Until 9 months later where he awkwardly does a semi-apology and tries to change the subject. Unless there is a good excuse... let the friendship die a quiet death, right?