If you want to screw up someones brain or make him get nuts:
This magic screw and nuts is the right thing for you.

On this magic screw you fasten one nut clockwise - and the other one counterclockwise.
But only the normal thread is (easily) visible.

If you print it in black (with e.g. 8mm thread), the backward thread is nearly unvisible and looks like printing inaccuracies of the normal thread.

Tip: Put both nuts loosely on the bolt and hand it over to somebody whom you ask to try the quality of the 3D-printed thread by
a) simply unscrewing both nuts OR
b) tightening the nuts against each other OR
c) holding both nuts with two fingers while turning the screw.
=> A stupic face is guaranteed :-)

You can easily customize this magic bolt with its nuts as you like, the OpenSCAD file is also attached.

If you have never used OpenSCAD - don't panic. It is just 50MB to install and not difficult to use for customization. Just follow the simple instructions in the last picture how to do this.
(Remark: Preview of the changes in customization is quick - but rendering the screw to generate the stl file takes some minutes on my old slow laptop.)

If you don't want to customize this, you can use the attached .stl files.
(Hint: If the nuts are too tight on the bolt, it helps to change the "horizontal expansion" parameter in your slicer to a small negative value.)