I've never really gotten up the nerve to ask another guy about this, but for those stud machines out there who apparently have complete and total control over when and where and how much they cum as a minor effort of will; how exactly did you get to that point? Has it always been that way?
So far the best I have come up with on my own is the stop/start method. I know when I am about to cum, and exactly how close I can get to that line, but I can't stop the forward momentum without stopping everything. Even well back from the danger zone there isn't any plateauing or establishing a holding pattern; it just builds until I know it is time to stop or finish. I have been with and seen plenty of guys who have been right on the edge for minutes at a time and there was no letting up on the amount of stimulation they were getting, but through sheer willpower prevented their brains from sending the signal for them to cum.
If it is possible to learn such a thing I am your willing student. So if any Jedi masters out there have words of wisdom, please share.