I have struggled with labels. I think it's more like you are poly in nature but choosing a lifestyle of monogomy on your side.
See-I'm bi. But currently I have a husband and a boyfriend (no girl there).... so I'm living a "straight" lifestyle, but that sure as hell does not stop my motor from running when I see a beautiful woman... no doubt I am actually bi. Just not in a bi relationship.
I am finding that I am getting less and less interested in labels with my age as well.
They just seem to be more complication than they are help for me these days!
I think it's just part of the growing process.