Well it turns out I may have over-reacted. It was actually only one person out of the group who added my husband as a friend on FaceBook . None of the other people had added him, so I must have misunderstood what he'd told me the first time.

So at least I feel better and less left out now since it turns out it was only one person and not several people. I may decide to send a friend request to that one person, but they live out of state and I likely won't actually see them again in the near future... so I'm ambivalent as to whether I'd want them as a FB friend anyway.

But I feel much better now, and I really appreciate your comments and suggestions.