Thanks for all of the good advice. It is probably the body contact and that sexuality is an important part of the basic foundation of ballroom dance itself that causes my problem of jealousy. The environment is probably not particularly "charged", being USA Dance promoted dance parties. It is even held at a local church after all.

I talked to my wife about it and she really didn't seem to want to see my perspective and suggested my jealousy is just a lack of self confidence. She is correct, but those insecurities are seated in cultural norms that have a basis in reality. All will probably turn out fine, I think I probably just need to get more comfortable with the environment and the people in it.

My thought (as a woman) is to realize people generally bond with those that they enjoy shared experiences. You should go, just as she should attend things you may enjoy, whether it's biking, sports events...it doesn't have to be all-day events. I think this is so important for a relationship. It's not necessarily a jealousy thing, but while she is bonding to others and enjoying their company and she is also removed from the reality of taking care of a family and home for those few hours, just her going is intrinsically motivating.

Most men who say they don't enjoy dancing, actually just don't feel comfortable dancing, especially if their partner is better than they are on the dance floor. This is a self confidence issue, that can easily be fixed by you spending the time learning to be a better and more confident dancer. Not only will your wife appreciate it, but you will find that you are enjoying being a dancer. I would almost bet that you both learned to dance together? Right? If you did, then its no wonder she feels better about dancing than you do. Women are "led" through many many steps on the dance floor by different partners, often having no idea what they are doing, but because they learned to follow a good leader they enjoy themselves and learn much quicker than their husbands.
My advice, schedule dance lessons for yourself only. Your Teacher will be able to spend quality time teaching you and you will improve significantly in a very short time. Maybe you will learn to Love Dancing!!

It's normal that spouses have different hobbies. It seems to me that you need to trust your partner more.