So is the original poster owner of the video? Or did that page just post a video, which you then reposted on your page via the "Post video" thing, but you don't actually know who is in the video itself?
If that's the case, the "original poster" isn't the "original", but rather someone who has either downloaded a video from a porn site and added a watermark, or not even that. There are many shady websites where people download adult videos from, and a lot of the time they are non-consensual, especially homemade ones. Sharing this on Twitter can get your account into trouble, as they have an obligation to obey the law, unlike porn sites hosted in Russia or Belize, etc...