Mixed messages

My sister and I started going to this certain gathering place at the same time. The first day, we were there, a guy I'd previously known a little came up to me, initiated conversation and started suggesting activities I could participate in. They all happened to be ones he was also involved in. Since then, over several weeks, he seems to be staring at me constantly, asking questions, and agreeing with most of my comments, even when I'm talking to other people or in a group. He has hugged me or touched my shoulder multiple times, is usually hanging around, and has gotten my phone #. We see each other at least 3 times a week. Now, out of the blue, he suddenly friended my sister on facebook, even though he rarely talks to or looks at her. She is significantly younger, still a teen, and hasn't got much in common with him. He still hasn't friended me. He has inititiated any contact with so far, so I'm not being wierd about this. This is really strange since he seems to be leading me on or something. Any insights?

It seems like he really fancies you and it seems like he is doing all the chasing so he might be unsure of how you feel and doesnt want to befriend you on facebook in case you reject him. And probably hoping that by befriendingvyour sister so that you feel abit jealous and will want to befriend him and like him more. So if you like him or feel that it could go somewhere then you show get to know him better. Hope this helps.