Well, actually I can be already in the game. She is sister of my friend, we met in some parties and in one of them I was kissing with her. And also one other Guy was doing She was rotating between (she revealed me, that she likes kissing) and it ended as draw - she went home with brother. I screwed up, because I didnt hold Cat String Theory (which was effective).
my first question
how it is with ioi, when you are not only one, who is receiving them.. what should I think about it?

well, I hadnt time to invite her somewhere for weeks, so we chat on FB sometimes (I think, that i couldnt keep raport for so long, so at least I wasnt forgotten ), and she started dating with that Guy. Her brother told me, that she isnt sure if he is the right. I was okay with that. We met this week, they were together like week or two (I dont know, I tried to change topic everytime), they had and he left, so she spent rest of night with me and we were kissing again. After it, they break up (officially bcs that argue). Before that, she invited me to some conference this week and I didnt answer if I go.

and my questions are
I think, that she can be interested in me, but how I discover, that she isn't just using me? (and turn around it)
When to start game with freshly single girl (contact her that day to comfort, or wait days, week?)
Should I use that conference as pretext to contact her, or talk about other things (not her breakup, right?) and wait till she mentions it?

Everybody who finish this post has my admiration = D