About four weeks. I play with my tool in the shower a lot during that time, which felt amazing the longer I abstained. However, when I finally let it out, it was like jello. TOTALLY FREAKED ME OUT. I never want to abstain from ejaculation again. I think once a week is probably a healthier frequency, or lack thereof, for me.
Next longest time going without was 7 days. On the 7th night, I was at a friend's house, in their guest room. Had spend about half an hour enjoying the jets in their whirlpool bathtub. Went to bed. Pulled it out, and after about 2 minutes I had splattered my face with 3 ropes of jizz, with more for my chest and belly. I had to turn on the light and find something to wipe myself of with, and make sure I hadn't plastered any of there stuff, all without making noise or leaving the room! God that felt amazing!!!