Is it ok for her to force me not talk to someone she doesn't like?

Ok so my g/f introduced my to her friend, which is a girl, it was a one time meet for the majority of the day this was like at the begining of the year she friend requested me on FB i accepted it never on planing to talk to. About a month or too ago i started talking to her cause i am currently unemployed and i have no one to talk and she will be on occasionally so i will talk to when either of us are online and bored. I mention to my g/f that her (ex)friend isn't so creepy or weird as she made her seem and fliped out that i was talking to her and made it seem like she had a crush on me or something and she would rather talk to this other girl i that i i tried hooking up with after me and my current g/f broke up for a bit so i think it should be ok to be able to talk to her friend wheather or not she does like me cause nothing is going to happen between us cause the girl i talk to is dating someone and she shouldn't be forcing me as to who i can and cannot talk to.