There is a big difference being scared stiff of flying and freaking out.
I took a friend who was scared stiff of flying and asked whether he could come along on a twin flight. he was an avid film maker and turned up with his camera. I took him along to help him but lost an engine at 200 feet in the climb out.
he calmy fimed the whole event from takeoff to touchdown and wanted to come on any trip he could after that experience.
Another guy a super cool racing driver who displayed no nerves whatsoever lost the plot big time and froze on the controls when I gave him control.
he refused to let go and literally froze solid.
Both the above are true.
So take him along but also a gun incase he does freak and you need to put him out of his misery
Pace