Yet I also realized that, as at many large functions, guests were probably being invited in waves, so my having said “Yes” most likely prohibited someone else from being invited. I’d cast a net over a metaphorical table of delicious viands; I was a dip-blocker.

A friend who is a former diplomat in India wrote in an email: “The aspirational R.S.V.P. is a fact of life in India. You never assumed that simply because a guest R.S.V.P.’d that meant they intended to attend. On the morning of a dinner we were hosting for a prime minister once, our local staff were frantically calling invited guests to ensure that they were actually going to show up. It didn’t work — there were several high-profile absences who had informed us at least twice that they would attend.”

Such absences, he wrote, “precipitated a game of name-card shuffle on the tables.”

“While cocktails were being handed out in the ambassador’s living room,” he wrote, “staff members were in the dining room pulling chairs and closing gaps, and switching out name-cards to place whomever was the next-ranked V.I.P. closest to our guest of honor. On one occasion the ambassador was so infuriated that he called the absentees the next morning, but was no doubt greeted by blank looks on the other end of the line.”

My friend confessed: “I would be lying if I said I didn’t adopt the local custom.”

To be sure, context is important when gauging one’s misdeeds. It’s a far greater sin to go AWOL on an intimate dinner party than on a foodless gallery show or a body-packed rager. Moreover, “Yes” in New Delhi or on Facebook may have a different valance from “Yes” in Boston. And yet.

What other dark forces prompt an aspirational R.S.V.P.? A celebrity or V.I.P. may say she will attend, particularly if it’s a fund-raiser, so that the hosts can brag that she’s coming. Others do it in a deluded hope that cataclysmic, paradigm-shifting events will occur, thus ultimately allowing them to attend — their boss’s announcement of gender reassignment will derail the company picnic; cousin Sue’s wedding will be rescheduled when her chocolate fountain clogs and burns several bridesmaids.