Sexual orientation might not even be a big deal in the SW universe. Are there even any sexual scenes in any of the books?
Some people have accused Ziro the Hutt of being a flaming gay stereotype, although there is no onscreen evidence of it.
In the Marvel comic, former Senator Simon Greyshade and his shiny pal Master Com might have been the first robosexuals though. At least the parody comic Jaxxon's 11 ran with the idea. ;)