For me personally cumming isn't just the single moment of orgasm its a gradual building of mental and physical sexual energy combined with a tightness and hardness in the penis as blood continues to fill over the course of the experience and it gets harder and harder and you yearn more and more for release. I feel a building up of pressure and wetness as pre-cum starts to steadily release and lubricate. Eventually it becomes a frenzy of primal lust as the experience overwhelms my rational thoughts and orgasm becomes more imminent. Pressure continues to build and I feel a feeling of inevitability as if I am basically just controlling when the release will happen, no longer if it will happen. It is all out of my control at that point and I can only hope to get maximum enjoyment out of the experience by controlling it for as long as mentally and physically possible. The experience reaches a new level of intensity as I reach the final point of holding back where it takes everything I have to keep from finishing. At that point the physical and mental flood of endorphins and sex rage is virtually uncontrollable, my dick is rock hard - completely engorged in blood like some kind of behemoth of sex energy - and I feel like my entire being is focused on each millisecond of time passing before my eyes as I yearn for release but don't want to end the experience quite yet. Then I release and I feel an emptiness as my heart rate quickly drops back to normal, endorphins flood my mind, my pupils dialte, and my dick goes into overstimulated remission. I am spent and at peace and yet yearn to return to that frenzied state.