I'd say that if you are kissing & cuddling you are in fact BF/GF. Perhaps you are not each others' exclusive BF/GF - that's something you should probably discuss - and you may not want to advertise your status, but I think you are more than "just friends".
"Boyfriend" and "girlfriend" are not well-defined social status like "fiance' " or "husband/wife". Just introduce her as "my friend", "my co-worker", "my classmate", etc. Your behavior and interactions with each other will convey the nature of your friendship. It seems to me that when somebody feels compelled to introduce someone as "boyfriend" or "girlfriend" they are trying to post some kind of a social "No Trespassing - Do Not Touch - Prosecutors Will Be Violated" sign when in fact there is no generally recognized basis for it.. . . if we are with each other at some sort of get together I dont want to make a joke of myself and introduce her as my GF when she thinks otherwise.