The famous question we men often ask ourselves: How on earth do I last longer in bed?
Let's remove the word 'bed'; it's so boring and routine. How about rephrasing the question like this:

HOW DO I LAST LONGER LITERALLY ANYWHERE????

Let it be public bathrooms, on board the train or the backseat of a cab with the tinted glass separating the driver and the passengers, the key to a longer screw bugs now and then especially when you're done in twenty minutes!
Don't worry guys for I have a couple of techniques, which I have personally used to give me the extra time we men crave for.
The first important element to remember is learning the art of self-control.
Try exercising the male kegel muscles that are responsible for stopping your urine flowing half-way.
Masturbation is an excellent way you can flex these muscles to help restrain yourself from climaxing too early.

Another method I have tried, which does help prolong the intercourse is imagining you are doing anything else but having sex! You must be thinking, "How the hell am I going to distract my thoughts when I've got my penis in some woman?!" Now, before you conclude this is impossible, give it a go. As for me, I would imagine somewhere far in my mind playing golf. Unless you have some fetish for a golf club, it shouldn't sexually set you off. So physically I'm thrusting back and forth while mentally I'm somewhere in the Bahamas swinging a club.
It is a known fact men easily get off compared to women. So guys show some courtesy by putting her pleasure first before yours. Stimulate her with sex toys. Have role-playing sessions. Even if you're on the verge of shooting your load, just do it and continue pleasuring her. The secret here is to keep the 'fire burning' so that both you and your partner enjoy the sex and how fast you climax may not be an issue.