Where can I find this video?

There is no video. This is a homemade Witcher 3 doujinshi

Here's the original post.
http://lordaardvarksfm.tumblr.com/post/127381620193/when-the-witchers-away

Here's a list of all the actual sex scenes in the game
http://kotaku.com/every-sex-scene-in-the-witcher-3-1706995209

There is no video. This is a homemade Witcher 3 doujinshi

Here's the original post.
http://lordaardvarksfm.tumblr.com/post/127381620193/when-the-witchers-away

Here's a list of all the actual sex scenes in the game
http://kotaku.com/every-sex-scene-in-the-witcher-3-1706995209