I agree with what Ygirl said. If you're wanting to form a new love besides what you have with your wife than, yes, sounds as if poly could be a word to describe that.
Interested to hear how your maybe-date goes! I'm also in a couple that is wanting to form a triad ... bisexual woman, hetero man, wanting to add a mutual girlfriend... that elusive "unicorn" although from the intense mockery and scorn I've seen around the community on the topic I'm a little scared to admit it! Too bad I'm already in a couple; if I were single I guess I would be a unicorn myself because I view the triad as such a strong functioning family unit. I don't want to have children and the idea of having both a husband and a wife is so appealing...
Anyway! If what you are here to seek is support than you certainly have it!