I'm one of those unlucky ones. Prostate cancer surgery ended ejaculation, so I have to be happy with a dry orgasm. At least I'm still alive and no do not have to receive a prostate exam.
In my case the times I orgasm without ejaculation is during edging, when the stimulation stops before I reach the point of no return. If I cross that point I am not able to hold the ejaculation in. Actually I love the full orgasm without restraint after some edging that I don’t try to keep it in. For those girls who like the ejaculation, the reward is that I give a little more semen at the end, plus lots of precum during the edging.
I have no ejaculation mostly after 2 or 3 times masturbation in a day. It happens mostly for old guys who I am one of them.
I had many orgasms whem playing with my cock as a kid before my first ejaculation at 11yo, And when I'm edging I take myself so close to shooting my load many times that when I'm ready to cum it feels like I've had multiple orgasms.
I masturbated to a climax three times yesterday and managed to ejaculate each time, the third time was somewhat thin and not as copious as the first. At 66 my ejaculations are not like they used to be, but I still manage it.