The foil-embossed invitation for a destination wedding on a tropical island hits your mailbox, and the instinct is familiar: make an excuse, and quietly hope no one asks why. For tens of millions of Americans, that excuse has a name, and it’s not one they’re willing to say out loud.

Two-thirds of Americans have skipped at least one social commitment in the past two years because they just can’t afford it, according to a new survey from the CFP Board shared with Fortune. The events they’re missing out on aren’t always luxuries. They’re birthday dinners, concerts, holiday gatherings, as well as group vacations and weddings.

But in most cases, people hide the real reason they can’t accept the invitation. Of those who declined invitations, 56% never told their friends or family that money was the reason why they couldn’t attend, according to the report. CFP Board, the professional body for personal financial planners, surveyed more than 1,100 Americans aged 25 to 64 in January for the study.

Most Americans are skipping social events to save money—and staying silent about it

The silence is telling, and it’s only making Americans lonelier and anxious about sharing their financial status with friends and family.