To pull out. It's inspired by the act of unsheathing a sword from its holster, and just happens to perfectly resemble the mechanism of pulling out your... sword... during intercourse.
"Bruh, I was about to cum, but I sheaded so quick. I ain't bout to become someone's baby daddy."
This is the reply one should use when some idiot attempts to tell you how you shoulddo something you already deal with on a regular basis and that they have never experianced and know nothing about.
Mr. Knowitall was once again getting on everyones nerves by telling them how they should complete the job when one individual shut him up by blurting out, "shaddafuckup".
When a guy's fat gut is so huge it resembles a hippopotamus head ... it therefore must be a hippopotamus that only has 2 legs and has purchased itself a lovely man's head for a hat (probably not such a lovely hat given the size of the gut)