[scwtlover]

Cut the Gordian knot. Call the hostess and ask.

IMHO, this imposes an unecessary, and possibly unfair, burden just a week before the wedding.

As the invitation was for you + guest, I think that, from an etiquette viewpoint, you may bring someone else. (How that may affect your current relationship may be a different matter.)

 

[scwtlover]

Making a phone call to the hostess does this?

Yes. She has many other, more important things on her mind. And what is she supposed to do? Worry about whether saying no will offend one of the groom's best friends?

Perhaps, however, as the father of an about-to-be bride, I'm over-reacting to someone we invited individually asking -- through his/her parent -- whether we also would invite his/her girl/boyfriend.

 

[scwtlover]

If two people are known to be a couple, it's considered improper to only invite one of them. If you don't know them to be a couple, then only inviting the one you know isn't improper, but it sounds like the parent thinks the relationship is sufficiently stable, so it would probably be best to let the other person come.

That's well and good, but the venue has a hard cap on numbers. We can't, and don't want to, not invite our relation. Yet, until we see how many invitees rsvp negatively, we can't put the boy/girfriend ahead of the people we have invited. Of course, space permitting, we'll extend an invitation.