The sperm can stay alive for at least 3 days. It can remain in you swimming around. Depending on its job, it will be looking for an egg to fertilize or another man's sperm to block and kill. If it's not absorbed into your body, it will be evacuated normally. I have a microscope, and have seen sperm alive and wriggling 3 days after being bred by a man. Most sperm I have checked is still alive after 2 days, but 2 men I checked lasted 3 days.