Cyndi Lauper Shares the Secret to Her 33-Year Marriage to Husband and 'Best Friend' David Thornton (Exclusive)

Cyndi Lauper and her husband, actor David Thornton, will be celebrating their 34th anniversary this November.

Their big secret to marital bliss? Just enjoy hanging out together — and don't stress out about small things.

“You have your highs and lows of course,” Lauper tells PEOPLE of marriage. “But sometimes the things you think are important when you’re young just aren’t important."

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Lauper adds that it's important to remember that your spouse isn't just your spouse, but also your family.

"Your partner is the best friend you’ll ever have, that you’ll spend the most time with. So you have to talk to them, share stuff," she says.

Lauper and Thornton first met on the set of the 1991 movie Off and Running. Though they started off as friends, they soon began to fall for each other. In an interview with The Independent in 1992, Thornton said, “She began inviting me to join her for dinner regularly, and after a couple of weeks it dawned on me that I really liked her an awful lot."

On Nov. 24, 1991, the duo got married at a Friends meeting house in New York.

“Neither of us is a Quaker, but we liked the idea of friendship and tolerance being the theme, as our friends come from all walks of life and all kinds of political and sexual persuasions,” Thornton said in the same 1992 interview.

On Nov. 19, 1997, Lauper and Thornton welcomed their first and only child together, a son named Declyn.

Lauper is about to kick off her Girls Just Wanna Have Fun Farewell Tour in Montreal on Oct. 18 and says she's particularly excited because she never did do another big arena tour after welcoming Declyn.

“I was an opener for other acts at arenas, then I got to do one big tour for myself,” she says of her rise to fame in the '80s.

"Then I got pregnant with my son, and I was worried I couldn’t do a whole show, so I went back to being an opener again. So watch out, kids, once an opener, always an opener!”

Lauper notes that her entire family shares a love of music. "David loves art music, though his taste in music is different," she admits.

"When our son was growing up, David always listened to electronic dance music, which is popular now but was more underground in the ’90s. Declyn was more interested in Green Day. Either way, it was always a dance party at our house.”