There is no way to prevent that. You may possibly make someone who knows nothing about the internet and who isn't really interested enough in your content to think for a couple of minutes believe that it is possible. But our computers only display what they have already copied.
The best way is simply to write on your site: "Please don't copy this, because.....".
Any stupid javascript tricks are likely to be counterproductive.
The web works by downloading everything to the visitor's PC before their browser can display it. Once that is done the visitor has your pictures and trying to inhibit clicks cannot change that.