Download the Share on Facebook Blocker to watch YouTube videos without having to share it. This is an extension that shows videos directly in a webpage, and it also doesn't require you to share the video in order to watch it.

This doesn't need the Facebook app, it only needs the internet browser. 

This application needs permission from YouTube™. The video you see is embedded in the same page so you can easily start viewing it.

You can also hide the splashscreen that some websites show when you visit them.