I know the most graceful way to do a b-list is not to have one, or if you have one, not to let the b-list know they are on the b-list, but here is my story...
My wedding is at the end of May. I started a new job in October when I had pretty much finalized my list. Over the past few months I've become really close with a group of my coworkers. We are social and hang out. They know my wedding is in May and it comes up in conversation sometimes. They know my wedding invitations have gone out already. I really wanted to invite them, but by the time we sent out the invites, my list was too full (mostly due to my fiance's large family, which I've complained about to them), and they were on the cusp, so I didn't invite them. I really want them to come, especially now that a lot of people have RSVPed no. Is there a way to gracefully invite them, or should I just forget it at this point.