I would not want to see a homosexual relationship on screen in Star Wars at least partly because it would be controversial (whether or not you think it should be). I don’t think Star Wars movies should include anything that is hugely controversal in the real world, regardless of whether it’s something I support or not. I want Star Wars to be a fun escape from reality, not a reminder of it.
Let’s say the new Star Wars movie established that the Jedi forbid transgender operations (far-fetched, I know, but it’s the principle that counts). While many people, including myself, think that changing one’s sex is wrong, I would just as disappointed that it was included as I would be if one of the characters changed genders, since it’s a controversial issue in the real world.
So, whether or not you think that gay marriage and whatnot should be controversal, the truth is that it is, and I do not want any controversial issues from the real world appearing in a movie that is supposed to be an escape from reality.