Cordially invited and completely stumped

From my inbox: “I have been invited via an e-mail service to a prenuptial party for a good friend of mine. The party is hosted by friends of his fiance, with whom I am not aquatinted. My partner of five years, who also knows my friend and his fiance, did not receive an invitation and there is not an option to leave a note about a plus-one on the service they are using to collect RSVPs.

”My inclination is to decline, but only because I cannot think of a polite way to bring up what I hope is an oversight. I feel strange bringing it up to my friend because he is not actually hosting the party. I do not know the hosts, and do not have a way to contact them directly, and yet I want to avoid an awkward encounter at the door in case there is a list (it is being hosted at a private club).

”Finally, if I go by myself and I am asked by my friend where my partner is, I would prefer not to have to tell him the truth that he wasn’t invited. How should I proceed?”

This is a flaw in many e-invitations—they go to an email address, but there’s no indication of “just you” or “and guest” or “bring/don’t bring your roommates.” How would you advise this writer, and how do you handle in general the gray area of electronic invitations?

— Carolyn Hax

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