Is there any point of a fly on underwear? some arent so easy to use. who wants to be standing at the toilet trying to open the buttons and busting for a piss at the same time. some have a slip towards the side where you have to reach ur hand in, find the other slip on the other side and the twist the undies to get the cock out. i would use my fly sometimes to pull my cock and balls threw (like a cock ring) to create a bulge in my trousers.