Share Rented Youtube videos?

I know there are other posts related to this topic but I was still a little unsure about it. Is it a 100% guarantee that two parties who both rent the same movie and are logged into their Youtube accounts, would be able to watch it together using. If you could please confirm that would be great.
Thank you.

I tried it for myself and i know that other users have tried it as well and it worked. The only issue i can see is with Safari since this browser blocks all 3rd party cookies and therefore breaks Youtube’s authentication in the embeded player. But a 100% guarantee is hard to give since it involves a 3rd party (Youtube).