OK, so heres a breakdown of my situation..

This girl (HB8.5-9) has been my girlfriends best friend for a few years, but I had never met her. This is due to the fact that for this relationship, I agreed with my girlfriend that we would keep our friends separate while we were going out so as not to cause animosity on either side for the future (Has happened a fair few times before).

My relationship came to an end approximately one week ago (was a 1 on/off year relationship), but it had a fairly friendly end, with us both agreeing we each needed to go our separate ways in life.

I met her best friend for the first time last night, and we immediately kicked it off. At first, I didn't want to get too close to her, so I'd introduce her to my friends (With great intros for them as well), and take my leave, but every time within a minute or two, she'd be back sitting at my side, leaning on me, laughing at every one of my jokes, very open posture towards me, with mild kino on her part. I even double checked by throwing some lame jokes out, which I knew none of my friends would laugh at, but she did (She is fairly intelligent), consistently making kino by putting her hand on my leg or head on my shoulder almost each time (No, I didn't reward her actions with either attention or praise, she was just doing it).

So... my dilemma is more an ethical one, as I do still care about my ex-girlfriends feelings...

Should I keep pushing her best friend away?

Should I mess around with her, and not let the Ex find out?

Should I just do exactly what pretty much every ounce of me wants to do and start gaming her?

Have you guys had experience in this kind of situation? Am I walking into a trap of some kind that will inevitably turn very sour?

If I do start gaming her, where do I start going from? Kino has been constant, but I have shown zero attraction to her so far (I made sure to keep unconscious body language under control as much as I could).

I would appreciate any input you guys have to offer.

-Chromantic