On Dec. 2, Rachel Birthistle and Roberto Bernasconi stood in front of their wedding guests at Passalacqua, a luxury hotel on the shore of Lake Como in Italy. The gathering was intimate, and the space charming. Everything felt traditional — until the vows.

At the appointed time during the ceremony, the bride and the groom handed each other a sealed envelope. Ms. Birthistle silently read Mr. Bernasconi’s first. Then it was his turn. Guests watched on as music, instead of the sound of the couple’s voices, filled the space. Several minutes later, the two were pronounced husband and wife.

“I was concerned there’d be an awkward pause, and I’d see people get shufflely,” said Ms. Birthistle, 54, a wedding planner and the owner of the Lake Como Wedding Agency. “But that didn’t occur.”

When she finally glanced up at their guests, many were crying, she said, adding that “the whole experience was unexpectedly meaningful, especially when I could see the emotions and expressions on Roby’s face and know what part of my vows he was reading.”

Vows have long been a classic part of weddings, but some couples are turning the moment into something more intimate.

The online wedding company Zola, which recently surveyed more than 5,000 people with weddings planned for 2025, said in a report that a vast majority of respondents thought exchanging private vows was trending and loved the idea.