In terms of our friends in relationships, my fiance and I are inviting both spouses of married couples, both partners of engaged couples, and both partners of couples who are living together. Our remaining friends are either single or in not-very-long-term relationships. We'd love to invite them to bring dates, but our budget won't allow for that unless several invitees decline to attend. So, here is my question. If after we send out our invitations, we receive enough replies from guests not attending to equal the number of single friends, can we then casually invite these friends to bring a date if they like? Or is that in poor taste? I would never do a b-list round of invitations, but I'm not sure if plus-ones for guests who have already been invited fall into the same category. I don't want to be rude and tacky, but I also want as many friends to enjoy the company of a date to the extent our budget will allow. What do you think? Thanks in advance for your advice!