psychological

“Everyone has to make a decision about how much engagement they can tolerate without undermining their psychological well-being,” he said.

And once his kids are older, he may start taking different parts — maybe a psychological thriller or an indie film.

These soldiers are “trained to withstand a high degree of physical pain and psychological torture”, says Michael Madden, a North Korea expert from the Stimson Center in Washington.

The caution was "understandable when spas were first open" but research has shown massage for patients can be "highly beneficial to their physical, psychological, and emotional health and wellbeing", they added.

"And to understand that impersonating or pretending to be somebody… it's not victimless. It is very real and its psychological impact is particularly strong."