Why/when does a guy's penis pulsate?

Like is it only when your hard or is it after you ejaculate? When I was kissing my boyfriend and sitting on his lap I felt it pulsate about 4 or 5... Show More

Updates:
pulsating = spasm?

Most Helpful Guy

  • If a guy has a boner he can pulsate as many times as he wants, and no it doesn't mean he jizzed in his pants.

    • Are you saying that you can do it on purpose?

    • With an erection yes.