This is very simple.Do not run the mooring pennant to your bow cleat. Do not run a single line from port to starboard bow cleats thru the mooring pennant eye - you'll saw off your line or saw off the eye. Run a port line from the port bow cleat thru the pennant eye back to the port bow cleat. Run a starboard line from the starboard bow cleat thru the pennant eye back to the starboard bow cleat. No need to mess with a 3rd line to the pennant if you've checked your two primary mooring lines for wear.