Before she settled down with her now-husband, Katie Williams made something clear: She planned to take herself on one big trip, plus several shorter ones, every year.

Williams caught the solo travelling bug in her 20s. She spent a year visiting 30 countries across four continents on her own.

“It lights me up,” said the 36-year-old, who now lives in Boise, Idaho, and works as a travel blogger. In the eight years she and her husband have been together, she has taken another 40 or so solo trips – to Egypt, India, the Maldives.

“People say, ‘I can’t believe you do this without your husband’,” she said. “They think it’s a red flag, or that we have a horrible relationship or something. But I think you can have a stronger relationship if you can be an individual within your relationship and do what you love.”

Solo travel is a booming business – and a popular topic on social media. There are more than two million #solotravel videos on TikTok, many extolling the virtues of hitting the road on your own – adventure, self-discovery, freedom.

But vacationing alone when you are in a committed relationship elicits more mixed – and often quite heated – reactions.

On forum platform Reddit, commenters warn that wanting to travel without your better half is a harbinger of marital doom: “the beginning of the end”. Some guiltily ask if they are jerks for wanting to travel alone. Others argue vociferously that wanting to take all of your vacations together is a sign of codependence.

Couples’ therapists say all of those dynamics can be true.

“Travelling separately isn’t inherently good or bad,” said Justin Pere, who runs a therapy practice in Seattle. “It just amplifies whatever is already happening in the relationship.”

Solo travel can bring up big feelings for couples because it forces them to grapple with the balance of autonomy and interconnectedness in their relationship, sai...