If you don't REALLY want to come to our wedding, RSVP "No". I won't mind, I swear.
I DO mind, however; that you nonchalantly make up some lame excuse not to come when we say "see you in 2 days!" Seriously, I now have to pay for all your meals.
On that note, FMIL: I have to pay for that plus one you RSVP'd for 3 weeks ago. I admit, I was truly shocked when I asked what his name was and you said that you haven't met him yet... but I thought you'd at least bring a friend instead of stiffing me with another meal and telling FI you don't really care how much it cost.
And hey Mr. Officiant: I hired you primarily as a comedian, you remember that? I added you as an officiant only because it was convenient. I've been looking forward to your act since oh 6 MONTHS AGO when we signed a CONTRACT. I appreciate that you're not leaving me high and dry on the ceremony, but the next time you want to cancel on someone, maybe it's a good idea to give them a phone call, rather than an e-mailing them. Maybe you'd like to offer to find a replacement...and maybe, just maybe, you wouldn't retract the discount from the package pricing that we negotiated. Maybe you would also subtract the money spent on your mail too from the total??