I'm sorry that I was hopelessly vague in my first post. It was really late and I had just gotten home from work.
I'm female, my partner is male (I hate the terms husband and wife when applied to my life, not sure why) and our friend is male. In thinking about it more, it's not that my partner is horribly traditional, he is actually quite progressive. It's just that I'm so far off in left field that by comparison, he seems to be terrible traditional.
In terms of talking about it with our friend, I don't think that he is the one necessary, but rather it opened my eyes to the possibility of "hey, this could work." Since things have been going so much more smoothly, I really sat down and thought about why. It's like my partner and I are a cart with two wheels. Sometimes we balance just great, but other times it's really wobbly. But with three wheels, it's alway at an even keel. I think I would prefer a relationship where we were all romantically involved, and as I'm bi and my partner isn't, I have a feeling a FFM triad would work better than a MFM V, but I could be wrong.
Thanks so much for your replies so far. It's so nice not feel like I'm the only one in world the feels this way.