You may well fall in love with someone else, but as long as you truly love and are committed to your wife, it in no way has to mean you would leave her! This is an important thing for her to come to understand. The whole idea of poly is *multiple* loving relationships, not replacing anybody. It can be hard to understand the idea of loving and actively being in a relationship with more than one person if it's new to you, but more reading may help. There are great resources for beginners at www.morethantwo.com
Best of luck!
Me, 30ish bi female, been doing solo poly for roughly 5 years. Gia, Clay, and Pike, my partners. Davis, ex/friend/"it's complicated." Eric, Gia's husband. Bee, Gia and Eric's toddler.