How do you prolong ejaculion?

First, you have to know the signals that your body is about to ejaculate. You can learn to recognize the signals by masturbating. When you feel the signals, you can try

• to stop moving. Some times the lack of stimulation will be enough.
• Think about something non-sexy (politics, crabgrass, your job, etc.)
• pull out and do something that turns your lover on that's not particularly exciting for you -- massaging feet, maybe.

You can also try masturbating before intercourse, or continuing to stimulate your partner after you ejaculate -- use your finger or tongue, for example. It will take you a while to build up another head of steam, and meanwhile your partner will be getting more and more excited.