We're having a small wedding. Do we have to invite Mr. Smith "and Guest"? One friend told me that if he's not seriously dating someone, I can just address the invite to Mr. Smith, and he'll know he's not supposed to invite someone. Is that true? What do I do if guests reply for two anyway?
Your friend is right. Most guests will understand that without "and Guest" or another name on the invitation, it's meant for them alone. Especially if you're having a small wedding, you probably won't invite singles to bring escorts, except for serious significant others. Technically, you're not supposed to write "and Guest" -- you should find out the significant other's name. Even so, you'll probably see a decent number of invitations addressed to "and Guest" in your life, because it's easier than asking all the single guests whom they're planning to bring (that doesn't make it right, but what can you do).
What to do if some clueless souls reply for two? Call them up and explain that you are having an intimate wedding and unfortunately were not able to invite everyone with a guest. People should understand. Don't feel bad -- it's your wedding, and only the people who are explicitly invited are supposed to respond.
Wedding Invitations + Wedding Stationery