Yeah um... it's actually called orgasm?
and cum is an action of liquid shooting out from your reproductive organs, (including girls, uh huh)
so~ they usually say "I'm cumming", and I'll leave the rest to your imagination.
However, because "come" sounds similar to "cum", so a lot of people (mostly asian) believe that both works since if you translate "come"... it's... yeah...
Anyways~ 不懂的自己去查
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