it depends who was around when she referred to u as "friend"...if it was her grandma or something, that i can understand, because i've done that. but if shes calling u her friend infront of her other friends and/or guys...somethings up. that may be just the way she is...but its obviously bothering you, so you should mention it to her. i think it depends on how long you've been with her also...a few weeks compared to a few months or years makes a big difference, to me at least.
all in all, its not appropriate. it bothers you, so talk to her. dont flip a lid, just ask her why she only says "friend" and not "boyfriend".
and to whoever it was who asked about the Fiance thing....i think calling her your girlfriend is fine...i, personally, get sick of hearing the word "finace". :dunno: