Ian and Larissa Murphy were college sweethearts who knew they were destined to be together forever from the day that they met. Unfortunately, they couldn’t have predicted the major obstacle that would stand in their way…

This is Tori Boggs, she's a nine-time world rope-skipping champion, a two-time rope-skipped world record holder and captain of the U.S. National Jump Rope Team.
 

That's quite simple, you just need to remove the polarized layer from your computer screen and use new polarized sheets to make polarized glasses out of 3D glasses for example.
Only the person wearing the special glasses can see what's on screen, others will just see a blank monitor.

Better try that first on a used monitor you don't care about though...