What is the best way to say no children or men allowed on a baby shower invitation?

I am co-hosting a baby shower for my sister and we are making arrangements to have all of our children and husbands occupied elsewhere for the event. Traditionally baby showers are a women only event, but we were quite annoyed two years ago when she threw my baby shower and many guests showed up with their children and a husband.... How can we word our wishes to leave significant others and kiddies home, without offending anyone?