It will be reabsorbed / recycled as long as there is no periodical need for release. If there is a need every once in a while, the body will simply continue to stress itself as to meet your demands. No factory, unless repaired periodically, can sustain the same production rate for too long.

The body is 100% efficient (no waste materials admitted) when in good working condition. Also it will produce no more or less than what there is demand for. When you acquire the discipline to clear your mind from sexual thoughts and not give in to external stimulus, the rate of semen production will diminish or even cease.