My friend has become very touchy, and it bothers me a bit. Any idea why?

She hung with me while everyone ordered at a restaurant. Then we ordered at the same time, filled our drinks at the same time, and waited for our food at the same time. She then sits next to me and touches me on the shoulder and upper leg MANY times during conversations. She keeps scooting closer and closer until we are touching from shoulders to hips. We are friends and we both decided we did not want any more, so why would my friend be doing these things? I am confused!