There is no rule when it comes to swinging club outfits. You will find that there are a lot of different people that will wear a lot of different things. It all comes down to what you like and what you feel the most confident, sexy and comfortable in. Many people will only focus on how things look and not worry about the practicality of it. Be sure that you understand what type of outfit will work best whenever you are in a swinging club.
It is really important that you are comfortable in what you are wearing. You will find that if you are constantly pulling at your outfit or trying to cover up parts of your body that are exposed that you are not going to have a good time at all. The more comfortable you are the better off you will be whenever you are choosing swinging club outfits.
You will of course want to look and dress sexy whenever you are at a swinging club. Just make sure that it is something that you feel sexy in, not what you think others will see as sexy. If you feel sexy in jeans and a T shirt, then that is what you should wear. The confidence that you feel while you are wearing the outfit will be what people really see as sexy.
Think about how easy the outfit is to take off. If there are a lot of buttons and zippers and strings, then it is not going to be a very popular outfit to have to maneuver around.