I Last Too Long

It can sometimes work in reverse . the more you dont want to cum the quicker it comes and actually when you want to cum you cant for all the tea in china .
I take it you find her attractive and its not just a fuck cause your young . Just try some different things out together and like the others have said . cut the wanking out man . you got a girl that can sort you out now so you dont need to be beating your own meat like a mad man .

 

Okay, I've heard of guys who come too fast, but none who last too long.

It could be that you're too nervous. Don't concentrate on the orgasm or worry about it, that could be what's holding you back. Just enjoy the experience!

Alternatively you could masturbate with your partner (since you always cum when you jack off) and show her what you like and what you don't. Take it from there.

As a last resort get condoms that offer extra stimulation.

Hope I helped!

L_S