* No heavy breathing...keep your breathing at a normal rate.
* No pelvic thrusting...keep control of your hips
and finally, but most importantly:
* No twitching your cock muscles! Keep your cock under control. This will probably be pretty challenging for a horndog like yourself...but you must not under any circumstances allow your cock to twitch.
Do you think you can follow these rules?
If you do happen to twitch or tighten your PC muscles in any way while you are stroking you must keep a count of how many times this happens.