FI's mom asked us to invite a distant cousin and his wife to the wedding. She was pretty excited that he might come, because although my FMIL lives on the other side of the country, her cousin lives about 2 hours from where the wedding will be. FI apparently met him when he was a baby/toddler, but knows nothing more about him. We do not keep in touch. I believe the cousin and FMIL stay in touch only via the occasional FB message. The couple has been on our list from the beginning.
We sent separate RSVP cards for each invitee to the wedding- so this couple, John and Jane, each had their own card to indicate meal choice, attendance, etc. We just got back HIS declined RSVP, with no indication of the wife. He sent a note and a check, which was very nice. The note is signed by just him, and (not that this means anything definitively-) only his name was on the account holder info/address on the check.
I'm somewhat thinking maybe we were misinformed and perhaps they are no longer together? Or am I reading into this too much? The question is: should I address a thank you to both of them, or just John? I know it doesn't seem like a huge deal, I just don't want to keep rubbing a separation in his face, nor do I want to slight his wife.
FMIL is unable to answer the question, and I'm quite sure she'd tell me "whatever you think" regardless. Sorry if I'm making mountains out of molehills... it's a nice distraction from actual planning/decisions.