Is it wrong not to include "and guest" on a single person's invitation if they are not in a relationship? As the groom's parents we are limited as to the number of guests we can invite. I need answers fast! Thanks!
It is perfectly acceptable to invite a single person without including a guest.
Also you may want to note that putting "and guest" on any invitation isn't really acceptable either. You should find out the guest's name and either send them their own invitation or include their name on the invitation of the person invited to bring a guest.