Alright, this guy is either drunk or 12.
By his screen name, I think I may be able to extrapolate the former.
But, just for shits and giggles:
If you friend is flirting with her (or you? whatever), big deal? It should be a non-issue.
If she wants to bring her friend along, it's either, as Waccoon pointed out, that you aren't being clear on what exactly your intentions are (which can be easily solved by telling her), or that she isn't yet comfortable or confident enough to be alone with you in a romantic sense. In that case, just take it slow. If you really want to be with this girl, or are interested, you can be paitent with her, I'm sure.
So, no big deal. Just, as I said before, play it by ear. You should be fine, hell, even if you are drunk, this isn't
that difficult.