frequently applied to fornication, but may apply equally well to masturbation
When applied to intercourse as fornication 3 pump chump is a misnomer because the chump is really the jizz orifice (woman). While the average penis is seven inches long this is likely to effect those with longer than average penis as there is more surface area to receive pleasurable stimulation. The average penis girth is five inches. Those with above average girth might be victims of her jizz orifice applying too much additional stimulation suddenly albeit unconsciously.
If her jizz orifice is the victim of 3 pump chump with average or above average penis it is likely the male has a low- or zero refractory period allowing for extensive practive to overcome pump limitations