Today I told a guy I liked him and he responded really weird...?

I had the feeling he liked me. He'd stare at me quite often. He was pretty shy around me yet more open around other girls. He'd approach me but never say anything. Sometimes he'd mumble and just talk really fast when I talked to him.Anywaysss aha so today I told him and he was just looking at me kinda expectant but not bored, like listening. Um so when I said 'I like you' his face didn't change, almost like he was expecting it.Then after 2-4 seconds he just held out his hand for a handshake and um I shook it. And were 14/15 years old so... I don't get the handshake thing... And throughout the entire thing he did'nt say anything.... Please help! I don't understand this at all! :D Thankyou! It's appreciated!