I went to a pool party 2 weekends ago, met a girl, got a k-close, she seemed way into me and there was a lot of chemistry, she initiated kissing after that like she wanted more, but she left the party 30 minutes later without saying 'bye', and I never got her number. She mentioned that she was a cousin of the guy who threw the party, so when I got home I searched for her on his friend list and sent her a friend request on facebook.

Now it's a week and a half later and she just accepted the request. She lives about an hour away, but she's from this area and her cousin still lives here, so I assume she is in the area sometimes.

Any ideas on how to proceed? Not sure what the best way to open a girl on facebook that I've already opened once and kissed, if I should ask for her number right away, or flirt a little first, etc.

I wouldn't start a chat right away if she took 10 days to accept your friend request, but liking something is cool.

Getting the number is something you will want to do, but it's not a priority. I'd probably start a conversation and steer it towards something you could do together. My favorite FB opener is "Do you like hot dogs" but obviously that is situational, and you don't want to use canned material on FB.