ok im a girl n my suggestion i read all of these and compared to the 20 yr old ur lucky lol im not tryna brag or make u feel bad my bf is 15 also and is 8inches n he is constantly askin if i like the size of his. and i tell him yes but he still gets a bit paranoid about it.
maybe sit ur gf down n talk to her if u feel insecure about it ask her if she rele likes it. or if she wishes it was bigger.
let me say tht if i was her i would deff be satisfied with it.
with wat the one person said bout her just bein horny.. she rele prolly just is and just wants u to get as deep as possible. if she is pulling u in it prolly doesnt hurt her tht bad she prolly loves it n u just get her extremely horny.
so my advice talk to her if u feel need to and be happy with its size. u still have years to grow as well so.. u have no worries