Last winter Trysta Barwig was burned out.

She was overwhelmed by her job as a program manager and she was traveling too often for work from her home in Atlanta. She needed a break. So when Ms. Barwig’s boss asked her to pack her bags again, she used what had become her go-to excuse: a Covid exposure.

“I figured this would be easier to tell my boss than having to answer a million follow-up questions of why I couldn’t go,” said Ms. Barwig, 31, who is also the founder of a travel blog This Travel Dream. “He was very supportive and excused me from traveling for work.”

Problem solved.

As Halloween and other holidays lurk around the corner, plans are picking up in some parts of the world. And so too is social anxiety, at least among those who are naturally introverted or who might be feeling a little rusty after about a year and a half of restricted interactions.

Some people have started lying about Covid exposure, figuring it’s the one way out of plans —from work to dates to dental appointments — that few will argue with. Others have been using the lie all along.

Of course, actual exposure to Covid is no joke, and lying about it is a luxury that many people, including huge numbers of essential workers who risked their health over the course of the pandemic, don’t have.

Dr. Larry Burchett, an emergency room doctor and family physician in Berkeley, Calif., said that those who are unvaccinated and are actually exposed to someone who has tested positive for Covid should quarantine for 14 days even without symptoms. Vaccinated individuals who have been in contact (within six feet of someone for at least 15 minutes) with someone who has Covid don’t need to quarantine unless they have symptoms, but they should get tested five to seven days after exposure, Dr. Burchett said, in accordance with C.D.C. guidelines.

But even permission from the C.D.C. to skip quarantine if you’re vaccinated and not showing symptoms doesn’t stop some from deploying the lie.

Back in March, before many people were vaccinated, John Junior thought he had met the perfect woman online. Mr. Junior, a mental health activist from Cheshire, England, chatted with her online for two months before arranging to meet in person. He bought movie tickets and made reservations at a bowling alley, only to get the dreaded Covid excuse on the day of their date.

“She messaged saying her uncle dropped some presents off a few nights ago, and he said he has symptoms of Covid,” said Mr. Junior, 33. “She said to me she can’t leave the house in case she has Covid.”

Mr. Junior was skeptical of her story, so she upped the ante, telling him she had actually tested positive. She sent him a photo of the test over Snapchat, he said, with a black marker clearly used to create a positive result. It’s the third time Mr. Junior had a date cancel because of alleged Covid exposure, he said.

Sara Bernier, the founder of Born for Pets, a blog providing pet care tips, has been on the other side of the equation. Last year, she met someone online and had plans to meet him, until he started sending suggestive messages the day before their date.

“Since I have a difficult time saying something as simple as ‘no,’ I made an elaborate story about getting Covid, and how it would be impossible for me to show up,” said Ms. Bernier, who is 29 and lives in New York.

Therapists aren’t surprised that Covid exposure has become such a convenient — yet also horrific — excuse for our times.

“For people who want to avoid doing something, whether due to anxiety, existential dread or the idea that it would be easier to stay in and watch ‘Squid Game’ than get dressed and go out into the world, the Covid excuse seems tailor-made: It’s timely, prominent and appears driven by an altruistic concern for your friends, co-workers or strangers’ health,” said Suraji Wagage, the co-founder and director of the Center for Cognitive Behavioral Therapy in California.

“It’s difficult for the receiving party to react negatively without seeming like they don’t care about others’ health or the spread of the global pandemic,” she said.

Bonus: The excuse can be recycled without necessarily arousing suspicion, as you can potentially be exposed to Covid repeatedly and at any time, Ms. Wagage added.

But it’s precisely because this excuse is so good that it poses its own risks, she said. By spending so long leaving the house sparingly, if at all, we’ve conditioned ourselves into limited socialization. As a result, it’s more difficult to do what seemed ordinary before, such as meeting friends for dinner or even going to work in an office.

That’s been the case for Daniela Sawyer, the founder and business development strategist for FindPeopleFast, a web-based background search site. She loved the antisocial lockdown period in New York, so she continued it post-lockdown by telling everyone over and over again she had come in contact with someone with Covid.

“This excuse seemed so natural, that they couldn’t deny it at all,” said Ms. Sawyer, 32.

Using the exposure excuse is simple and almost addictive in its ease of acceptance, but it could land you in jail.

After William Carter, a Dallas firefighter, allegedly lied about having Covid so he could skip work to go on vacation in March 2021, he was arrested and charged with felony theft (he was paid more than $12,000 for the time he was on vacation). He is on paid administrative leave while under investigation, according to the city of Dallas.

In July, Santwon Davis of Atlanta was sentenced to three years in prison and ordered to pay $187,550 to his employer for wire fraud related to a scheme to defraud his employer when he requested and received paid time off from work for what he claimed was a positive Covid-19 test.

Mr. Davis was accused of submitting a fake medical record to his employer, a Fortune 500 company, which shut down the facility in which he worked for cleaning, and paid all the employees during the shutdown. (Investigators also uncovered that in 2019 Mr. Davis faked the death of a child — one who did not exist — by creating and submitting false documentation to the same employer to support a claim for bereavement leave.)

But those are extreme situations. When someone pulls the exposure card to get out of a date or even a wedding, is it so different from using your kids as an excuse not to go, well, basically anywhere you don’t feel like going?

Jamie Hickey, a human resources specialist at Coffee Semantics in Philadelphia, said he and his wife were supposed to attend two weddings within a 10-day period this past June. They really didn’t want to go, but couldn’t think of anything that would get them out of both events with one swift lie.

“So we told them that I had a close encounter with someone that has since tested positive for Covid, and I had tested positive but was not having any bad symptoms,” Mr. Hickey, 42, said. “We told them we didn’t want to come to a large event and possibly pass along the virus to anyone else.”

The lie worked a little too well, and the couple was inundated with phone calls, texts and emails from dozens of people making sure the Hickeys’ were OK. Did they need soup? Medical care? Assistance of any kind? Covid is, after all, no joke.

Finally, Mr. Hickey admitted that they lied, which led to many lectures about his lack of morality.

“In the end,” he said, “it may have been easier to just go to the weddings and drink for free.”