We had a party last week and one of our friends who said he would be there never showed up. Do we call him and say something, or wait for him to bring up the subject?
By all means, call him. Just say, “Henry, we missed you at the party and are hoping nothing was wrong that you couldn’t be with us?” This give him the chance to apologize and explain and clear the air so this isn’t an issue that becomes a wedge in your friendship. He may have forgotten, or had an emergency, but whatever the reason, politeness dictates that he reply. He should have initiated the call and explained, but since he hasn’t, it’s fine, and actually important, that you be the one to smooth a situation that could just be a big misunderstanding.