I am 22 and i have the same situation as yours. I have hooked up with a girl recently, and we talk on phone. i have not told her that i stutter. 2 days back, we had a 5 hour marathon phone session , in which there were moments of stutter, like a prolonged "aaaa". And there were moments when i spoke very fast. But she did not get the idea that i stutter. I am yet to meet her. I don't know whether i will stutter or not. So, still undecided whether i should tell her or not. I do not stutter as much in general talks but when giving presentations and speaking to a higher management authority, i am not able to speak. I am highly optimistic and i think this presentation/talking to higher management authority stutter will go away. But this is just me. I would appreciate your reply. And yes, whether i should tell my GF about my stutter by hiding it, as in, talking less and speaking in a low tone. I have hardly followed any forums, books or speech therapists, so you can assume i have no idea about how stuttering progresses.