"People use both come and cum as a verb to mean the experience of having an orgasm, and/or ejaculating"-  из первой ссылки Гугла.  И вторая ссылка "Come vs. cum: the seminal battle" https://stronglang.wordpress.com/2015/01/12/come-vs-cum-the-seminal-battle/ .  Прочитайте, грамотейка