There's an excellent companion mod for Morrowind called Agony and Rapture, one of the few mods that contains a male/male romance. Not only that, it's a really good male/male romance - reasonably realistic with lots of playful situations, steamy goodness, and a touching storyline. Oh, and Marc's actually a good companion, too!
The mod was released as a beta version in 2005 and was never completed. It was complete enough to play and enjoy, but had some flaws. In particular, the storyline becomes broken at one point because there's no indication of how to advance the plot. I was enjoying this mod immensely and successfully used the construction set to repair the storyline and make small improvements.