How do you change the mood to play with a Boy?

There is this boy at school and i really like him and he knows that already. So he told me lets first be best friends and i said ok. But now that he said that, i am tring to adjust my-self to him and hang around all playful like what i always do. But he looks soo cute and hot, that i end up talking to him and, i think, he thinks i am boarding. So to be the way i am is all jumpy and excited but the guy i like looks all bored and tried all the time. But i know he is cute and fun cause i remember in the library we where laughing and joking up the whole time.

But my Poblem is that i don't know how to change the mood?

What would be something to say or some ways to change the mood to be happy and playing around and also be your self?How do you change the mood to play with a Boy?
you can make him jumpy one day by not bein all jumpy and act all layed back maybe even sad How do you change the mood to play with a Boy?
Ask. It might be an awkward conversation, but then you'll know. Just start being a tiny bit less perky for a while and see if he notices. There might be something going on in his life that is causing this, so be open.