How to be less jealous?

My wife is a gorgeous, beautiful, and unimaginably charismatic woman. So every guy she meets seems it be enchanted by her. Lately though. I feel so jealous. Especially since our new neighbor is some single 20-something year old with huge muscles. I'll admit I'm not very attractive, and I know my wife doesn't have feelings for anyone but me, but every time he talks to her I get so jealous! How do I control this?