It takes too long ...

That's interesting.

???

absolutely... i'm seconding this. first time i had sex i thought i'd go off like the flash but i didn't and luckily i've been blessed with some sexual stamina. just tell your girl that it's not her fault (because it isn't... you just have a large threshold) and point out the fact that she can enjoy sex a lot more because, thanks to your sexual longevity she'll be able to orgasm at least once!

Don't worry about it, really, it'll only make issues worse. Everyone's different and take different times and feel things at different intensities. It's all good, but if you want to make it easier on her, then suggest maybe she use a hand too. Or you could treat it as a form of foreplay, before sex, or any other sexual activity. It's up to you really. Just experiment and take your time, and you'll both find the things that work best for you have fun!