when my gf is giving me a handjob she goes for like 10 maybe even 15 min and all that happens is i get really hard and only precum and she doesnt think it feels good unless i cum and i want to to but it just never gets there.. is that my fault or is there a way she could do it better so i cum faster?
Lots of precum
Lots of guys don't cum easily in this situation because her stroking rhythm will not be the same as the one you're used to. You could try not masturbating for a few days beforehand to build up extra horniness.
But your post in this thread sits rather oddly with your last one where you had an opposite problem.