i remember i was masturbating with a friend of mine at his sleepover thing and once i finished i passed out.
I guess much depends on just what you define as a masturbation session. I live alone & am always naked, and more often than not I am unconciously fondling my penis for hours on end, which at this stage is usually only semi erect, although is still very pleasureable. While this may technically class as masturbating, I never really think of myself as masturbating until I set into a proper session, with the resultant orgasm being reached after 10 - 20 minutes or so from the onset of the heavy duty masturbation.
hmmm ive gone on and off for 6+hrs, being interrupted by things, getting distracted haha but a lot of the time trying find the perfect ... incentive... to make it as hot as possible and make it all worth while haha weird, but eh. Every now and then it just goes down that way haha. Fucking great while getting close to not being able to hold it, but once its over i wonder why i wasted so much fucking time haha.
I did it for a little over 5 hours once, and many times for 3 hours. I find it better to do it for 1 hour and make it intense. Then you dick isn't too sore and you can go again later if you have time.