Here's another one my perverted mind came up with in the wee hours one morning. Of course I don't play with my wife (yet) but here's the general idea:
It's called "Don't Cum". She would unlock me and lube up my shaft with lots of coconut oil. She would start a countdown stopwatch, say 10 minutes. I would stroke myself using just my first finger and thumb touch tips from the bottom of the head to the base of the shaft. I wouldn't be allowed to take my closed fingers off of my penis--so my fingers would never come above the head. She has a second pace timer which beeps every 2 seconds. I would have to maintain pace and complete a down and upstroke in that 2 seconds. Occasionally she would call out either 1 or 2, with 1 being the tips of my thumb and first finger touching to 2 being the tip of my thumb touching the first knuckle of my first finger. The 2 causes a very tight grip and would usher in an orgasm if left on very long. I still would have to maintain the pace of stroking to one complete up and down per 2 seconds. She would alternate between a 1 or 2 grip. Maybe if I make it the full 10 minutes the next day we'd have PIV or reward BJ. But if I fail and make myself cum then locked for another indeterminant period of time.