Anna - from Sunnyvale, CA
It sounds like you are cutting the hole for the coupler too large. To cut a correctly-sized opening in your decorating bag, remove the ring from the coupler base. Drop the coupler base, narrow end first, into the bag and push it down as far as you can. Using a pen or pencil, for a featherweight bag, mark the spot on the outside of the bag where the bottom screw thread (closest to the tip) is outlined against the bag material. For disposable bags, mark a spot 1/4-inch BELOW the bottom screw thread. Cut an opening at the mark you made. Push the Base down through the opening. One thread should be showing. You can then place the decorating tip over the base and screw the ring onto the coupler, locking the tip in place.