Guy Friend Acting weird.?

My friend and I were at the mall with another. Friend A is a boy. Friend B is a girl. Friend A was being weird. He lightly tapped my and was holding my hand for a while. He also had his arm around me for a while. Friends A, B and I saw two stores. I told friend B I was going in one. Friend A decides to come with me. Friend B and I were trying on dresses and stopped for lunch. He asked if I was going to semi formal after he mentioned he wasnt going with another girl before. I said yes. He said good. He paid more attention to me then friend B. This was Saturday. Today he asked me for a hug and was pretty attentive to me. Whats up with him?