Q  We are invited to a black-tie event. My husband absolutely refuses to wear a tuxedo. Is it okay for him just to wear a dark suit, or do we have to decline the invitation?

A  You have to decline the invitation. Black tie means male guests are expected to wear a tuxedo and that is one of the requirements for attending. Only when the invitation states “black tie optional” can choice be exercised and a dark suit and dress shirt worn instead.

Q  My wife and I are having a small dinner party and a colleague of mine, to whom I had mentioned the party, just invited himself to attend. We were careful in our guest list and he doesn’t match the interest of our other friends. I said I’d check with my wife, because I didn’t know what to say. What could I have said immediately?

A  No one should ever invite himself to an event, no matter how much he wants to be there. You could immediately have said, “I’m so sorry, John — we’d love to include you but we are absolutely at our guest limit so I can’t invite you — but we’ll find a time to get together socially, soon.” Since you hedged, if too much time hasn’t gone by, you can tell him the same thing — you are so flattered that he would like to be there, but you just can’t make it work this time.

Q  Some close friends are adopting a baby and we would like to have a shower. Is this okay, and if so, do we have it before the adoption is finalized, or after?

A  It’s wonderful to have a shower, but it is usually best to wait until they have the baby at home, because, sadly, things can go wrong. Don’t wait for finalization — which, depending on the state, can be up to a year afterward. Find out all the particulars so you can share information with invitees — it may be that the baby is not a newborn, so you will want to share size information, as well as nursery color, and anything else that will help guests choose the perfect gift.

Q  In which order do I wear my engagement and wedding rings?

A  Traditionally, the wedding band is worn first on the finger, with the engagement ring second, closest to the tip of the finger. Legend has it that this is because the wedding ring is then closest to the heart.

Q  Is it all right, in a restaurant, to blow on food that is too hot?

A  Generally, no, it is not, because you are blowing across the table and your breath is hitting the person across from you, or hitting his or her food. Most people are cognizant of germs, and find this unappealing. Instead, take your forkful of food and just hold the fork in your hand until it cools enough for you to be able to eat it without burning your mouth.

Questions for Catherine? Send them to arts@hersamacorn.com