Two people raising a grown-ass woman as their son might have made this a scarier movie, actually.
And here's Jack Nicholson, apparently strolling around the set with several important bits flapping around in the breeze.
All shirt and no pants make Jack a dull boy.
Presumably later, after Jack got himself decent, he grabs his ax and takes a few wild practice swings. A process which the crew has obviously learned to work around:
"Aw, no, come on. That bed is a rental."
And that iconic blood-filled elevator? The one from your nightmares? Well it looks a lot less terrifying and a lot more tedious when you see the poor crew who had to mop it up afterwards: