We had polished off dinner, tucked the kids into bed and cracked open a bottle of wine. That’s when our guest pulled out a tiny change purse and took from it what my husband and I thought was a cigarette. It was actually a joint.

“This is my nightcap,” she announced, lighting up and inhaling in matter of milliseconds. “I hope you don’t mind.”

(ANTHONY BOLANTE/REUTERS) – Cannabis is now legal for recreational use in Colorado and Washington state and technically legal — although not yet legally available — for medicinal use right here in the District.

My husband is not categorically opposed to marijuana. But he’s not particularly keen on someone partaking in our vacation rental, with another set of renters downstairs and our children installed nearby on a blow-up mattress, so he pecked back: “That didn’t sound like a question.”

It was an awkward moment, quickly brushed aside by our collective desire to keep an agreeable evening relatively agreeable. But it led us to wonder — just what is the current etiquette on marijuana usage?

It turns out we’re not the only ones asking. At a time when smoking marijuana is increasingly mainstream, legal and socially acceptable — a recent Quinnipiac poll showed that 51 percent of respondents believe it should be decriminalized — when and where to inhale is a question flummoxing regular smokers, part-time partakers and nonsmokers alike.

After all, cannabis is now legal for recreational use in Colorado and Washington state and technically legal — although not yet legally available — for medicinal use right here in the District.

A new challenge is figuring out how we’re all supposed to navigate dinners, cocktail parties, barbecues and cross-generational family get-togethers as more people liken puffing on a joint to sipping a glass of wine, while others still consider it a malodorous habit that’s best done not at all, or at least far from our house.

Allen St. Pierre, the executive director of the National Organization for the Reform of Marijuana Laws and a smoker himself, says navigating the marijuana mores shouldn’t, in theory, be that perplexing as long as smokers follow the cardinal rule: “Do not use cannabis in the presence of others who are not keen on it.”

The challenging part, he said, is figuring out who’s keen.

Here in D.C., it is far from a partisan debate, something that both Republicans and Democrats struggle with. “It’s a cross-party issue,” said a 27-year-old aide to a GOP congressman who, like many interviewed for this story, preferred not to give her name, further highlighting people’s discomfort with this subject. She says she smokes often at home, but does so without telling her ultraconservative, 50-something boss, her co-workers, or even many of her friends. “It’s really hard to know how people stand on it.”

Perhaps most conflicted on the matter are the middle-aged among us who increasingly find ourselves socializing with friends, colleagues, the parents of our children’s friends, neighbors and our own family members — in other words, with lots of people with lots of differing ideas on what’s appropriate.

“Some people are very tolerant; they don’t care,” offered a 47-year-old financial consultant from New York who enjoys an occasional toke before dinner. But for others, he said, seeking an okay from the host “is the equivalent of asking: ‘Do you mind if I club this baby seal?’ ”

An outreach director for a Northern Virginia nonprofit group found himself rejected when an elementary school teacher and good friend declined to attend one of his parties. The friend had suspected, correctly, that pot smoking would abound.

“She didn’t want to be associated with it,” the 25-year-old said, adding that the prospect of appearing on a tagged Facebook photo scared her off more than anything.

To satisfy smoking friends without offending nonsmokers, some Washington-area hosts simply exclude nonsmokers from events where marijuana may be present.

“I get invited to the Super Bowl party and eat pizza,” said John Wetmore, a Maryland television producer. “But they don’t tell me about the party planned for a week later where people are going to get out the weed. Which is fine; it can prevent some awkward moments.”

But it can also lead to hurt feelings.

To avoid that, some hosts try to bridge the gap by invoking the take- it-outside rule, but that’s not effective in all instances.

Andrea Khoury, who founded the popular parenting site SuperNovaMommy, says that when friends and neighbors come over to her Fairfax County home for a dinner or a glass of wine, they would be wrong to think her yard was free terrain for smoking pot. “My neighborhood is prim and proper,” she said. “I think people would consider smoking around others, even outside, disrespectful.” (And, lest we forget, it is still illegal.)

It is a refrain heard often in a city where many residents — White House staffers, congressional aides, defense contractors, sundry government workers — hold jobs that require security clearances.

“You never want to put anyone in a compromising situation,” said a Columbia Heights political reporter who writes for a popular online journal.

He’s been to small D.C. dinner parties that include marijuana, but smokers are unequivocally discreet, more so than in other places he has lived.

“Someone might say: ‘Do you want to come upstairs?’ It’s just understood, and you disappear for a while. When you come back downstairs the people who are downstairs know not to ask anything. You just carry on.”

Etiquette experts say simple discretion is key.

“There is definitely something known as too much information,” said Jodi R. Smith, the author of five books about social guidelines, including “The Etiquette Book: A Complete Guide To Modern Manners.” In other words, there’s no need to tell your Great-Aunt Tilly, the strait-laced mother of your kid’s best friend or your boss that after your dinner with them, you plan to spark up a joint.

If you are in a social setting in which the host has okayed an after-dinner puff, Smith advises pot smokers to treat their stash as they would a bottle of brandy or a box of Godiva chocolates. “If you’re not willing to share, don’t take it out,” she said.

But what if you’re the host, as we were recently, and it’s your guest who wants to smoke? Do modern manners call upon you to say yes?

Absolutely not, said Cindy Post Senning, a co-director of the Emily Post Institute in Burlington, Vt. “It’s your house. And you have every right to set the standards of behavior.”

No doubt, it can all seem very prickly. But Post Senning, who has closely monitored shifting opinions on cigarette smoking, cellphone use and texting, says there is an end in sight. “We’ll have marijuana anarchy,” she said. “Then the rules will evolve.”

Kyle Spencer is a freelance writer.