Sex act in which you fist a girl in the ass, then pull your fist out and donkey punch her as hard as you can, and when you're done, you say "omae wa mou shindeiru" which translates to "you're already dead" in english.
The reason why Puffy and J'Lo broke up in the first place was because he pulled a Fist of the North Star with his rings on.
Fist of the North Star (北斗の拳 Hokuto no Ken?) is a Japanese manga series written by Buronson and drawn by Tetsuo Hara that was serialized in Weekly Shōnen Jump from 1983 to 1988, spanning 245 chapters, which were initially collected in a 27-volume tankōbon edition by Shueisha. Set in a post-apocalyptic world that has been destroyed by a nuclear war, the story centers around a warrior named Kenshiro, the successor of a deadly martial art style known as Hokuto Shinken, which gives him the ability to kill most adversaries from within through the use of the human body's secret vital points, often resulting in an exceptionally violent and gory death. Kenshiro dedicates his life to fighting against the various ravagers who threaten the lives of the weak and innocent, as well as rival martial artists, including his own "brothers" from the same clan.
The manga was adapted into two anime TV series produced by Toei Animation which aired on Fuji TV affiliates from 1984 through 1988, comprising a combined total of 152 episodes. Several films, OVAs, and video games had been produced as well, including a series of spin-offs centering around other characters from the original story.
Hokuto Shinken (officially translated as the "God Fist of the North Star", among other names) is the primary fighting style in the series. A martial art which is 18 centuries old, Hokuto Shinken uses the body's 708 vital points to destroy or heal from within. The art can only be passed down from one master to a single student, and thus the dispute between Kenshiro and his adoptive brothers becomes the central plot during the first half of the manga's run.