Deciding on who to invite to your wedding can be quite tricky. Here are some tips on how to make this a less painful part of your wedding preparations:
Set your boundaries. The best way to do this is to restrict the number of people you are going to invite. Remember that aside from the actual person invited, if they have significant others (such as a fiance, live-in partner, or spouse) also have to be invited.
If you are going to be strict about the count, then you can indicate in the invite that a seat is reserved for only one guest. If you are generous, you may indicate that the person can bring 1 guest. Just be careful and consistent about this.
If you want your wedding to be solemn, then you may also indicate in your invitation if you are allowing children or not. Or if you are, mention the ages. Usually you can exclude pre-teens, babies, and children. Do not make exceptions for anyone.
This is the same to teenagers. Anyone 18 years old or older should have separate invitations from their parents.