Now, I know that I cannot stop someone from downloading my videos and sharing, however I would prefer to have it to so that people do not copy paste links directly to my bucket. Thus, is there a way to make my bucket accessible only from my server/domain making the request? 

If it helps, I'm using jwplayer which loads from a xml playlist that has all the links. This playlist definitely can be opened and viewed from anywhere and is where I expect the easy copy and paste comes from. 

I don't want to mask the urls because that means my bucket is readable to everyone. There is probably some chance that someone will find the url of my bucket and the name of the files and connect everything together...