A friend of mine and her longtime live-in boyfriend told me this recent disaster story. A wedding invitation from a good, good friend of theirs had come in the mail, addressed to the boyfriend --"and Guest."
She was pretty hurt (she was actually surprised how much). Her boyfriend was livid! And when he complained to his friend, this is what he found out:
The groom -- poor guy! -- had lost a long argument with their stationer / calligrapher. The woman insisted that unless a couple was married, etiquette required the "and Guest" format. (Which is not true, as we know.)
My friend's not mad anymore, but that's because her boyfriend was pushy enough to inquire, so they now know it wasn't a deliberate snub. How many of those other couples on the guest list are going to be insulted -- but quietly so?
That stationer really did him a dirty trick. She's a pro; she should have more accurate research. And that's why you need to do your own independent research first.
Have you been given a bum steer by one of your vendors?