I suspect I know what the outcome of this will be (IABU), but just wanted confirmation.
Myself and my DH have been invited to a friend's wedding in a few weeks. The same couple were invited to our wedding a couple of years ago. I don't know them fantastically well, but like the couple and see them a few times a year for dinner/drinks/catch up.
For our wedding the couple didn't give a gift at all. We had a (subtle - not mentioned in invitations!) gift list. They also forgot a card (though sent a text saying sorry they had forgotten - I wasn't chasing!), but sent it on later.
For info, both weddings will cost roughly the same to get to/stay over at etc. We can afford a gift. But so could they (don't ask me how as I dont want to go into too much detail, but I know their financial position).
IABU (and super petty) to not give them a gift, as they didn't give us one? I suspect the answer is yes.