As you probably already know, marriage in Skyrim is not restriced by what gender you play. Alot of people see this as making same-gender relationships canon. However, it seems to contradict itself. For example: Camilla in Riverwood is deciding between two men, flirts with you if you're playing a male but NOT if you're playing a female, and yet you can marry her as a female.
That, and there are no couples of the same gender in Skyrim. Maybe they're there and we'll see them in a future expansion? But for my part, it seems more like Bethesda just not bothering to put a restriction on marriage based on what character you choose to play than making it lore-canon.
So what do you guys think?