I sometimes have one or two partial ejaculations before the final big one. I bring my cock almost to the point of cumming and then stop stroking. It usually gives one or two spurts and then stays hard and I can carry on masturbating. Is this what you mean? If you're interested, I think I have a video of this that I can post. I should warn you that I like to catch the one or two spurts on my hand and drink it as I find this makes me even harder. If that disgusts you, I could edit that bit out maybe.