In sex ed as a kid you always learn that the withdrawal method just definitely doesn't work. I know this isn't true but it does a high rate of failure. On average of the sites I've read it's about 30 - 40% but is this % the chance that he doesn't withdraw or pull out on time or that he has sperm in his Pre ejaculate? If not how else can it fail? Because on those sites they said thats percentage when done correctly? I've also read that if he hasn't ejaculated recently and urinated since then there won't be any sperm in his Pre ejaculate is this true?