Just for those lucky enough to be able to be multi-orgasmic here is what is going on medically so that you have understanding of the advantage that you have.
As you become sexually excited your body starts to produce a bolus of the hormone prolactin. Prolactin is in both males and in females. In a female, the hormone is secreted during lactation and nursing. It greatly reduces the desire for sex during that time. In males the hormone is found at relatively low levels and this is normal. What happens however is that as you become more and more excited the body readies a bolus of this hormone and as you ejaculate that bolus is launched. It normally kills the erection, increases the sensitivity of the glans of the penis and for a short time kills the desire for sex. A small percentage of men have first very low prolactin levels to begin with. For these gentlemen becoming aroused again is an easy task. A percentage of that percentage especially when younger do not throw the prolactin bolus. This allows them to remain hard, and to plow on to the next ejaculation.
As we age it is normal for prolactin levels to increase in most men. As the aging process takes place the rising prolactin levels will tend to curb the abilities of most men. There are some Rx medications available to reduce prolactin levels, but they are hideously expensive.
All FYI
Fuzzy Ken