Only about one in 10 Americans would feel comfortable talking about how much they make at a dinner party. In fact, people would rather discuss just about any other hot-button topic: romance, religion, medical conditions or even politics, according to a recent poll by Lexington Law of over 3,000 U.S. adults. And about two-thirds of those polled said they'd avoid talking about any of these sensitive topics at all.

That attitude carries over into more private settings, too. Money, especially, is still a taboo subject: Only one in five people say they would ask a friend their salary, according to the survey.

Norms are changing, though. The survey found that 25 percent of younger Americans (age 18-24) said they did feel comfortable asking their friends about their incomes. That's compared to just 9 percent of Americans over the age of 65.

Millennials are also far more willing to discuss their finances with their partners than older generations. And experts say that's helping make them happier.

A full three-fourths of millennials in committed relationships say they talk about money on a weekly basis, according to a new survey from TD Bank of over 1,700 U.S. adults. That's about 9 percentage points higher than the share of Gen X couples, and an astounding 31 percentage points higher than the share of baby boomer couples, who say they have weekly discussions about their finances.

"We're in a better place than we used to be because younger couples are more willing and open to talk about their money — and to address it directly, right out of the gate," Dr. Jane Greer, a psychotherapist and relationship expert, told CNBC Make It.

Don't miss: 75% of millennial couples talk about money at least once a week—and it seems to be working for them

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