Top menu nav css class applies to sub-menu items

Hi we're running wordpress 4.4 multisite and our theme developer (who's not available) set us up with a class called "stream" that we could apply to links and menu items to open our pop-up radio player. Our website is https://vision.org.au/vision180, we're using this class on navigation menu items as well as links. However, when I applied the class to a top navigation menu (Listen) it then applied the class to all the sub-menu items, instead of just applying the class to that item. I've tried to find the class in the 8 stylesheets that are in the html without any success. If you guys could give me some pointers it would be greatly appreciated. So far I've taken the class off the top nav menu, but it is applied to the sub-menu item "Listen Now" under the listen tab.

Thanks heaps!