DEAR MISS MANNERS >> My partner invited one of his friends to my home who, in turn, brought along one of her friends. It was an informal gathering, so “the more the merrier” was the order of the day.

That is, until this friend of a friend started incessantly puffing on his vape pen, without warning or permission, inside my home. I don’t know this vaper well, and was flummoxed as to how to handle the situation.

My partner insists that while it was strange that he vaped without asking, it’s no big deal because unlike cigarette smoke, a vape pen won’t stain or cause any damage. But even if that is the case, I’m not comfortable with seeing a cloud wafting through my home.

Am I being unreasonable? Is there a polite (and hospitable) way to ask him to put the vape away or to smoke on the deck?

GENTLE READER >> The reason etiquette objects so strongly to guests of guests is that they impose the duties of a host on you in regard to someone you did not invite.

Miss Manners reminds you of this to say that her solution will also work on intentional guests. The polite way to enforce a reasonable household rule (which yours is) is to provide a solution: “I’m so sorry, we don’t vape in the house, but we have a nice deck; let me show you.”

The guest may then choose whether to relocate or to vape later.

DEAR MISS MANNERS >> Are there etiquette guidelines for a wedding where the couple consists of a formerly married person and their affair partner during that former marriage (assuming that fact is known to everyone)? Should the bride eschew white? Should the officiating clergy skip the normal sermon on fidelity? Should the whole event be low-key?

GENTLE READER >> How to demonstrate proper contrition while celebrating the byproduct of one’s crime dates at least to the second wedding of Hamlet’s mother. But, as Queen Gertrude demonstrated, it is a problem that is not searching for a solution, as the celebrants are generally content to party on.

DEAR MISS MANNERS >> I moved into my neighborhood three years ago, and I’ve had about 10 conversations with one of my neighbors at the end of the block.

In our last two conversations, which took place about two weeks apart, it was clear that she didn’t recall ever speaking to me before. Both times, we talked for a bit, then she introduced herself; when she left, she said all the “nice to meet you” stuff one says when you meet someone for the first time.

Should I act like I don’t know her every time we speak, or is that patronizing?

GENTLE READER >> Pretending to have just met is only going to cause confusion. Better to remind her, gently: “You know, I’m sure we did talk about two weeks ago, when I passed by and you were trimming the azaleas. But it’s great to catch up.”

Please send your questions to www.missmanners.com.