system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How can people ejaculate twice in quick succession?

How do people do this? The second time someone ejaculates there is still cum left. Why wasn't that shot out in the 1st time?
gpt
The majority of semen is secreted by several different glands in the male reproductive tract during arousal/stimulation. It's not stored. Sperm cells are the only part that gets depleted and needs to be replenished, but even those won't all be gone after just one ejaculation. The quality of sperm does deteriorate with consecutive ejaculations though.