by stankyvag May 1, 2009
by omginbd May 29, 2008
When your girls giving you head and when your about to finish, she sticks her finger in your asshole so you shoot like a fire hydrant.
Boy: "Last night I was getting head and she made me hydro pump."
Friend: "I WANT HER TO MAKE ME HYDRO PUMP!!!!"
Friend: "I WANT HER TO MAKE ME HYDRO PUMP!!!!"
by Jamie hell December 11, 2016