I had fallen to sleep before my wife, but before falling asleep my mind had been on having sex.
I woke up early about 4AM, with a raging hard on.
She was sound asleep and even though my first thought was slipping inside her, I didn't. Instead I threw back the covers and started to stroke my cock slowly. I had also put my hand on her butt, and was gently rubbing it. About 20 minutes later I felt it happening, balls tightening, legs getting stiffer, butt clenching.
I had been stroking slowly for a long time, maintaining my hard on, but couldn't hold back any longer she pushed her butt back into me and I went faster and exploded. She then turned to face me and sat up on her elbow, when she did that I realized she knew and she leaned over me and kissed me, smiled and rolled back over and went back to sleep.