OP update:
Well, I decided to go to that 'party' (we went bowling with 6 people), there were two couples there with us. She wasn't as flirty as she was last time, but her friends were dropping subtle hints. One couple left afterwards and we moved to the house of the other couple. We played a board game and the mood was relaxed. That's when the tequila was brought out. :P
We played a drinking game and she and the other guy present were quite drunk, me and the other girl not so much (I drink more frequently, I'm a big guy and I was not playing the game so badly). Whenever I drink I do get a bad hangover and it hit me pretty early so I lied down on their couch. The other couple was doing their own things and she sat down next to me, caressing me with her arms and head. I subtly tried asking her how she felt about me, but she avoided answering (I'm not sure if she didn't understand me or if she was too shy to answer).
Anyway, I got fed up with doing nothing myself so I decided to kiss her after some time, since I could tell that she wanted to but didn't have enough courage to do it herself. That definitely did the trick and we spend the next 2 hours or so snuggling/hugging, kissing and talking... She confirmed what I already thought and told me she definitely was interested in me, for quite some time (much longer then I had expected actually, even before I started talking to her online). Eventually her friend kicked us out of the house (unfortunately her drunk boyfriend had said some stupid things and she needed comforting, the situation was a bit awkward with us kissing for the first time and the other couple having relation troubles... I won't go into that here, but I guess alcohol can also do that...)
We also talked about my friend (we also did that this morning online) so she does know how I feel about that. But I don't want to bother her with it too much at this moment. Anyway, should I tell my friend about it now or just wait to see if things between her and me get more serious? If it's up to me, they will.
>>8 and >>5 I do like her, I can talk and relate to her unlike any girls (atleast, in recent times), but I don't really believe in love at first sight and I think things like that must grow. I do want to give it a chance, I definitely like her enough for that.