Withdrawal is the oldest form of birth control on the planet. There's not much to explain, really. The guy pulls out before he ejaculates. End of story. Some people call withdrawal the "pull out method." Or you may hear people call it "coitus interruptus." The key thing to remember is this: You've got to do it right--every single time--for withdrawal to be effective. And how many guys do you know with that kind of total control?