This last month has been by far the most intense time of jacking off I have ever had. Not healthy for long term, but cool to try once. A couple weeks ago I had about three days where all I did was masterbate. I left the house for a few minutes in the evening to get some food, though I wasn't even eating much, as I'd easily jerk off for 5 hours at my desk or lying on my bed without going anywhere. I was cumming 3-4 times a day, and wanking it almost nonstop.
One evening I started jerking off around 7. I went through a few chat sessions, and just kept jerking and jerking until it was 1am or so. 4 hours later, when the sunlight was coming through my windows, I was still in the same place with my hard cock. I was in a trance, and finally came around 9am. I was exhausted and almost crying, maybe from the stress of sleep deprivation, but mostly from the incredible feeling it was to cum at that point. I had been masterbating for 14 straight hours, and it was absolutely awesome.