How can i last longer in bed i kno im only 17 but its way too embarising cuming after like 5 mnutes last nite i cumed and told her i didnt so i wouldnt get embaressed so now she thinks i just go limp sumtimes

Slow down. Stop occassionally. Think about how to pleasure her, and not how good it feels. If need be, think about something other than sex to make it last.

--------most guys wil say it take them a hour to cum but it more like 3 min to 7 min to cum .;-]

When you first go in your real sensitive so all you do is stop for a moment. give the nerves on the end a chance to calm, then continue your tunnel investigation.

take some time alone and Practice and find out that a pause and the right breathing at the moment will have you hard for up to 30 minutes and she will be thrilled---

Remember protection!!!

i myself am 18 and yet i know what you mean
i found that i was only lasting a few mins 5/6
8 at max
but i've found a few methods i've tried recently that work quite well
positions are one try some new positions because some are there to help you last a little longer (e.g: Cow girl - this being were the female is on top rather than the male)

also try just calming down
when you reach the point were you find your self waiting to explode just slow it down a lil and breathe

Just controll yourself
you may find that as you get into it you'll be able to
work with it a little bit more

remember masterbation is there for you to reach a climax quickly so don't judge how long you'll last one that
but just remember
Breathe
Be Calm
Be cool
And
Protection - This helps as well because it bounds parts of the penis making it a little less sensitive and some even numb you just slightly =D

remember these things and i'm sure you wont go far wrong diz man =]